rocD1 Family assigned · low auto-curated · to review

H37Rv Rv2322c · MTBC0 · 221 aa · 2594699–2595364 H37Rv (-) · RefSeq

Genomic neighbourhood (genome browser)

Open in full genome browser →

This gene (outlined) in its genomic context; arrows are neighbouring genes coloured by verdict. Click any gene to navigate. Pan and zoom in the full browser.

Annotation: from legacy to revised

Legacy (H37Rv / Mycobrowser)Probable ornithine aminotransferase (N-terminus part) RocD1 (ornithine--oxo-acid aminotransferase)
MTBC0 PGAP re-annotation—
Revised (this work)Involved in arginine metabolism [catalytic activity: L-ornithine + a 2-oxo acid = L-glutamate 5-semialdehyde + an L-amino acid].
Functional category (TubercuList)intermediary metabolism and respiration

Curation note: Added P16.5d: Mycobrowser-annotated gene absent from RefSeq NC_000962.3 (the atlas' original 3906-CDS reference). Foundation record from the Mycobrowser release + translated H37Rv sequence; heavy enrichment layers (structure, orthology, conservation, interaction) pending.

Auto-curated: this verdict and function were generated by rules from PGAP + Pfam + Foldseek and have not been hand-reviewed (flagged for human review).

In the literature (TB corpus sweep)

Named in the body of 7 paper(s) in Europe PMC full text, though in no title or abstract. Matched under Rv2322c (4), rocD1 (3).

A hit does NOT mean functional characterisation -- it may be a mention in a genome-wide table or screen (e.g. a differential-expression supplementary table), exactly the mechanism that revealed the Rv3222c/Sarkar2021 co-induction. Restricted to hits CORROBORATED by the H37Rv tag itself, the gene name, or a substantial/multi-alias hit count -- single-low-count-ortholog-only hits were excluded pending individual review (cf. Rv0027/Mb0028, a confirmed collision unrelated to Mycobacterium). Coverage limit (P52.4, measured 2026-09-30): the body-text part of this search only sees articles whose full text Europe PMC holds, about 8-13 % of the TB literature published before 2005, 21 % for 2005-2009, 40 % for 2010-2014 and 66 % since 2020, so the absence of a hit says little about older mentions.

This distinguishes a gene that is dark because nobody has looked from one that is dark despite having been studied. Source: .

CRISPRi vulnerability

Vulnerability index 0.16 (95% CI -4.15 to 5.24). A more negative index = more vulnerable to knockdown (better drug-target quality); indicative threshold VI ≤ -6 = highly vulnerable.

Quantitative CRISPRi knockdown, graded (finer than binary Tn-seq essentiality). Source: CRISPRi vulnerability index (Bosch 2021, supplementary Table S2 'mmc3.xlsx', bulk import via Europe PMC -- supersedes the per-gene pebble.rockefeller.edu scrape of phase46_crispri_vulnerability.py).

Caveat on this estimate. Bosch et al. flag this gene's vulnerability estimate as NOT certain, and here that call has a mechanical cause visible in the library itself: every guide targeting this gene is >=21 nt (str_span=0.254 on a 0-1 scale, near the genome floor), and guide repression strength saturates from 21 nt on -- so the library never sampled a partial knockdown for this gene, only the near-maximal repression plateau. The dose-response fit (and this VI) is therefore essentially unconstrained by data, not merely uncertain -- a limitation of the CRISPRi library design for the non-essential class (Bosch et al. 2021), not a defect in this specific measurement. n_guides=7 is descriptive only and does not predict this. Do not cite this VI as a standalone vulnerability claim.

Legacy record & comparison (Mycobrowser)

Mycobrowser functionInvolved in arginine metabolism [catalytic activity: L-ornithine + a 2-oxo acid = L-glutamate 5-semialdehyde + an L-amino acid].
Mycobrowser EC 2, ., 6, ., 1, ., 1, 3

The legacy Mycobrowser record is shown for verification. Mycobrowser is no longer maintained; its EC numbers predate recent nomenclature revisions, so a class change usually reflects re-numbering, not a conflict.

Curated reference (UniProt)

UniProt P71890 TrEMBL · unreviewed
UniProt nameProbable ornithine aminotransferase (N-terminus part) RocD1 (Ornithine--oxo-acid aminotransferase)

Functional vocabulary (eggNOG-mapper, orthology transfer)

COG category E Amino acid transport and metabolism
Preferred namerocD
eggNOG descriptionBelongs to the class-III pyridoxal-phosphate-dependent aminotransferase family
Orthologous groupCOG4992
EC number EC 2.6.1.13
KEGG orthology ko:K00819
KEGG pathways ko00330, ko01100, ko01110, ko01130, map00330, map01100, map01110, map01130

Orthology-based transfer (eggNOG 5.0.2, diamond). EC/KO/GO/CAZy are computed annotations, not manual curation; cross-check against the primary literature before treating a specific reaction as established.

Conservation & selection (intra-MTBC, 142 601 strains, snapshot of 2026-09-29)

pN/pS 0.691 · quasi-invariant (3 sites), pN/pS underpowered
Polymorphic sites (≥ 0.1% of strains) 1 synonymous, 2 missense, 0 nonsense, 0 frameshift

pN/pS from segregating SNPs (singletons removed) normalised by possible sites. Low pN/pS = purifying selection (a strong signal that a "hypothetical" is a real, constrained gene). A high pN/pS is ambiguous: relaxed constraint or positive selection (drug resistance, antigenic variation) inflate it; e.g. rpoB/katG/pncA score high here for resistance, not loss of function. A clonal disruption (one allele over a clade) suggests lineage pseudogenisation; a convergent one (many independent alleles) is typical of resistance loss-of-function.

Essentiality (transposon mutagenesis)

DeJesus 2017 callNE · non-essential
What the call meansnon-essential
TA sites (Himar1) 10 in the ORF — 0 in the essential state, 0 growth-defect, 10 non-essential, 0 growth-advantage. Saturation 0.800, mean read count 23.125. A region of the protein devoid of TA sites is invisible to this assay: nothing can be inferred about it, in either direction.
All 10 sites lie in this ORF alone (no overlapping CDS shares any), so the call is attributable to this gene.

Genome-wide Himar1 transposon essentiality in H37Rv (DeJesus 2017). An essential call (ES/ESD/GD) is strong, independent evidence that a "hypothetical" locus encodes a functional, selectively required gene — orthogonal to intra-species conservation.

Mutant phenotypes (conditional Tn-seq, MtbTnDB) in-vivo phenotype

Conditionlog2FCqEffect
fitness in mouse infection (in vivo) +2.810.036 disruption advantageous
differential fitness in a comparison whose nature could not be established (upstream metadata defect, see note) (undetermined) -1.460.019 required

Conditional fitness of transposon-disruption mutants across 2 significant condition(s) (|log2FC|≥1, q≤0.05), from the standardized MtbTnDB compendium. A negative log2FC means the mutant is depleted — the gene contributes to fitness in that condition. An in-vivo defect for a "hypothetical" is strong evidence it matters for infection, even without a known molecular function. Disruption (Tn insertion), not a clean deletion; genetic-interaction screens excluded.

Provenance note on a condition above. MtbTnDB labels this condition in vivo (Collaborative Cross mouse panel) and attributes it to Smith et al. 2022, eLife 74419. Both are wrong and for the same reason: its left arm, `mbio_H37Rv`, is the saturated H37Rv reference of DeJesus et al. 2017 (mBio 8(1):e02133-16, fourteen independent Tn libraries grown in standard medium), not a mouse strain, and the upstream generator read the token before `_vs_` as a mouse-strain name. The same sample is the in vitro control of six knockout screens in the same file. Measured here on rank correlation over 3971 genes: this condition tracks the other 81 first-order in vivo conditions at rho = +0.03, where those conditions track each other at +0.270 -- it does not behave like an infection measurement. What the comparison actually is could not be established, so it is reported as undetermined rather than renamed, and it is excluded from the in vivo count of this fiche.

Proteomics (mass spectrometry) detected

MS detectiondetected in 1 of 16 independent MS datasets
Integrated abundance7.21 ppm · rank 2804/3519 (20.3th percentile)

Detection by mass spectrometry is direct, experimental evidence that the protein product exists — orthogonal to sequence conservation and to Tn-seq essentiality, and especially decisive for a "hypothetical" locus. Read the dataset count as abundance, not as replication. Measured across this atlas (3,491 detected proteins), the number of datasets a protein appears in tracks its abundance almost monotonically: median 1.2 ppm at 1 dataset of 16, 27 ppm at 10, 392 ppm at 15, 1,325 ppm at 16 — three orders of magnitude. A high count therefore says the protein is abundant more than it says several independent experiments confirmed it. What the count does establish, at any value, is that the product exists.

Predicted localisation (DeepTMHMM + lipobox) no export signal, no TM helix

Predictionno signal peptide, no TM helix (DeepTMHMM class GLOB)
DeepTMHMM classGLOB

A verified absence of signals, which is not a compartment. No Sec/Tat signal peptide, no transmembrane helix and no lipobox were found on this sequence. The predictor reports topology and export signals; it does not measure where the protein ends up, so this page draws no cytoplasmic conclusion from it. In M. tuberculosis that reservation is not theoretical: the 12 Esx paralogues of this atlas — EsxA/ESAT-6 and EsxB/CFP-10 among them, the best-established secreted proteins of the species — carry this very call, because substrates of the type VII (ESX) secretion system leave no recognisable signal. « Secreted » and « no signal peptide » are true together here.

Transmembrane topology and signal peptide from DeepTMHMM (deep-learning reference predictor); lipoproteins from a (myco)bacterial lipobox motif. A sequence-based prediction of subcellular context.

Physico-chemical properties (computed, ProtParam)

Length221 aa
Molecular weight22.7 kDa
Theoretical pI4.8
GRAVY0.05 (hydrophobic)
Aliphatic index93.3
Aromaticity0.045
Instability index28.2 (stable)

Computed from the ancestral MTBC0 sequence with the ExPASy ProtParam method (Biopython). Descriptive biophysical context: a positive GRAVY flags a hydrophobic (often membrane) protein, a high instability index (>40) predicts a short in-vitro half-life, an extreme pI hints at compartment or binding partner.

Domains (Pfam, hmmscan --cut_ga)

PfamAccessioni-EvalueResiduesDescription
Aminotran_3PF00202 n/a– Aminotran_3

3D structure (interactive — Mol*/pdbe-molstar)

No experimental structure is deposited for this gene: showing the AlphaFold DB predicted model (mean pLDDT 93.5, very high), coloured by per-residue confidence (dark blue = very high, orange/red = low — treat low-confidence regions as unreliable, especially termini and loops). Drag to rotate, scroll to zoom.

Structural search (AlphaFold DB model, Foldseek vs PDB — genome-wide) pLDDT 93.5

PDB hitprobTM (aln)TM (query)TM (target)Seq. id.Cov. q / tE-valueDescription
3ruy-assembly1_B 1.00 0.98 0.93 0.53 44% 95% / 53% 8.9e-23 sig 3ruy-assembly1_B Crystal Structure of the Ornithine-oxo acid transaminase RocD from Bacillus anthracis
6hx7-assembly3_C-3 1.00 0.98 0.95 0.53 37% 96% / 54% 9.2e-22 sig 6hx7-assembly3_C-3 Crystal structure of human R180T variant of ORNITHINE AMINOTRANSFERASE at 1.8 Angstrom
7lom-assembly1_A 1.00 0.98 0.94 0.52 37% 96% / 53% 1.4e-21 sig 7lom-assembly1_A Ornithine Aminotransferase (OAT) soaked with its inactivator - (1S,3S)-3-amino-4-(difluoromethylene)cyclohexene-1-carboxylic acid
6hx7-assembly2_B-2 1.00 0.98 0.95 0.53 37% 96% / 53% 2.0e-21 sig 6hx7-assembly2_B-2 Crystal structure of human R180T variant of ORNITHINE AMINOTRANSFERASE at 1.8 Angstrom
2byl-assembly1_B 1.00 0.98 0.94 0.52 36% 96% / 53% 3.6e-21 sig 2byl-assembly1_B Structure of ornithine aminotransferase triple mutant Y85I Y55A G320F

Foldseek search of the AlphaFold DB model (mean pLDDT 93.5, gated at 70) against the PDB — a genome-wide extension of the ESMFold dark-gene search that also covers proteins beyond the single-sequence length limit. Confident structural neighbours (E < 0.01) shown.

Transcriptional regulation (signed TRN: ChIP-seq + TFOE)

Regulated by (7 TF) Rv0023 (represses) · Rv0047c (activates) · Rv0324 (represses) · Rv1674c (represses) · Rv1816 (activates) · Rv2324 (represses) · Rv3736 (activates)

Regulatory edges from the ISB signed transcriptional regulatory network (TF ChIP-seq binding, Minch 2015 + TF-overexpression response, Rustad 2014). An edge is regulatory evidence (binding and/or expression change), not necessarily direct. For a "hypothetical", membership in a known regulon (e.g. DosR dormancy, PhoP virulence) is a physiological-context lead, not a function.

Condition: Condition-blind by construction. These edges come from transcription-factor OVEREXPRESSION in a single laboratory condition, so a listed regulator is not a claim that it governs this gene in every circumstance. Measured counter-examples exist within this atlas (see Rv2516c, where the DosR regulon collapses under moxifloxacin while the gene itself rises). Read a regulator as 'capable of shifting this gene', and look for the condition before building a hypothesis on it.

Functional interaction network (STRING v12, guilt-by-association)

Explore full network →

Node colour = verdict, dashed = still uncharacterised; edge colour = evidence (green experimental, orange genomic-context, grey co-expression), width ∝ score. Click a partner to open its page; "Explore full network" to walk the graph.

Closest characterised functional partner: rocD2 (Rv2321c, (MTCY3G12.13), len: 181 aa. Probable rocD2,ornithine aminotransferase, highly similar to C-terminal region of other ornithine amino), high confidence (score 999, all STRING channels except text-mining; the partner is chosen on its genomic-context evidence).

Showing the 15 strongest of this gene's 23 partners at medium confidence (13 at high confidence). The table is an extract, not a neighbourhood: across the proteome the real median degree is 34 while the served median is 15, so no hub, degree distribution or centrality may be read on this table. None of the 23 partners rests on an interaction measured in M. tuberculosis itself.

PartnerProductScoreNo text-miningChannels (≥400)
Rv2321c rocD2 Rv2321c, (MTCY3G12.13), len: 181 aa. Probable rocD2,ornithine aminotransferase, highly similar to C-terminal region of other ornithine amino 999 999 ctx neighborhood:882 fusion:900 cooccurence:774 coexpression:810
Rv2323c hypothetical protein 984 984 ctx neighborhood:814 fusion:400 coexpression:820
Rv2320c rocE cationic amino acid transporter permease RocE 975 974 ctx neighborhood:795 coexpression:864
Rv2319c universal stress protein 962 961 ctx neighborhood:783 coexpression:826
Rv1187 rocA curated pyrroline-5-carboxylate dehydrogenase RocA 941 939 database:900
Rv2439c proB curated glutamate 5-kinase protein 923 915 database:900
Rv1658 argG argininosuccinate synthase 832 774 coexpression:673
Rv1659 argH argininosuccinate lyase 808 747 coexpression:676
Rv1654 argB acetylglutamate kinase 817 744 coexpression:684
Rv1652 argC N-acetyl-gamma-glutamyl-phoshate reductase 812 736 coexpression:678
Rv1656 argF ornithine carbamoyltransferase 792 723 coexpression:646
Rv1653 argJ bifunctional glutamate N-acetyltransferase/amino-acid acetyltransferase 800 719 coexpression:644
Rv1650 pheT phenylalanine--tRNA ligase subunit beta 717 618 ctx neighborhood:532
Rv2324 AsnC family transcriptional regulator 597 594 ctx neighborhood:590
Rv1657 argR arginine repressor 535 465 coexpression:426

STRING combines evidence channels (neighborhood, fusion, cooccurrence, coexpression, experimental, database, text-mining) into a 0–1000 score. The ctx badge marks edges carried by the genomic-context channels (conserved neighborhood, fusion, phylogenetic co-occurrence), which are independent of orthology and structure and the strongest signal for an unknown gene. The no text-mining column recomputes the score from data alone, so a link that does not depend on the literature is visible. Association is a function hypothesis, not proof: corroborate with the operon context and the primary literature before assigning a function.

Where the experimental evidence comes from, and why it matters here. STRING's experimental channel fuses interactions measured in M. tuberculosis with interactions measured in another organism and transferred to this pair by orthology. The two are not equivalent for this atlas, whose standing rule is that better studied elsewhere is not a function established in M. tuberculosis. Measured on the served network: of the 38 229 partner pairs shown across the atlas, 13 483 partner rows carry a non-zero experimental channel, and only 106 pairs rest on an interaction measured in M. tuberculosis itself — 0.3 % of the network. Those 106 are long-established complexes (ESX-1/ESAT-6, RNA polymerase with CarD and RbpA, the Pup–Mpa proteasome, gyrase, Emb, GarA with PknB and PknG, the Rel modules); no still-uncharacterised gene is among them. The reason is not a gap in this atlas but in the literature: there is almost no experimental interactome of this bacterium, IntAct holding 134 curated protein pairs for a ~4 000-gene proteome. A exp (transferred) badge is therefore a lead, never a measurement, and an absence of badge is not evidence that the pair does not interact.

Sources

  • Ancestral sequence & coordinates: Harrison LB et al. (2024), An imputed ancestral reference genome for the MTBC, doi:10.1101/2023.09.07.556366
  • Product annotation: NCBI PGAP on MTBC0; legacy from H37Rv NC_000962.3 (RefSeq )
  • Domains: Pfam-A via hmmscan --cut_ga — Aminotran_3 (PF00202)
  • Sequence-level signal: ESM Atlas (EvolutionaryScale × BioHub) — exploratory
  • Controlled vocabulary: eggNOG-mapper 2.1.12 (Cantalapiedra et al. 2021, doi:10.1093/molbev/msab293), eggNOG 5.0 DB (Huerta-Cepas et al. 2019) — OG COG4992
  • Curated reference: UniProt P71890 (TrEMBL, unreviewed)
  • Intra-MTBC selection: pN/pS and disruption from SPDI variants of 142 601 MTBC strains (this work, local collection vs H37Rv NC_000962.3)
  • Genome-wide structure: AlphaFold DB model (Jumper et al. 2021, doi:10.1038/s41586-021-03819-2; Varadi et al. 2024, doi:10.1093/nar/gkad1011) searched vs PDB with Foldseek (mean pLDDT 93.5)
  • Interaction network: STRING v12.0 (Szklarczyk et al. 2023, doi:10.1093/nar/gkac1000), taxon 83332, CC-BY 4.0 — 23 functional partner(s); context anchor rocD2
  • Essentiality: genome-wide transposon mutagenesis in H37Rv — DeJesus et al. 2017 (mBio, doi:10.1128/mBio.02133-16, CC BY)
  • Proteomics: integrated mass-spectrometry abundance from PaxDb 5.0 (Huang et al. 2023, doi:10.1016/j.mcpro.2023.100640), taxon 83332 — weighted average of 16 datasets, incl. Schubert et al. 2013 (doi:10.1016/j.chom.2013.04.008) and Albrethsen et al. 2013 (doi:10.1074/mcp.M112.018846)
  • Functional category: TubercuList scheme (Cole et al. 1998, doi:10.1038/31159), via Mycobrowser (Kapopoulou et al. 2011, doi:10.1016/j.tube.2010.09.006)
  • Transcriptional regulation: ISB signed TRN — TF ChIP-seq (Minch et al. 2015, doi:10.1038/ncomms6829) + TF overexpression (Rustad et al. 2014, doi:10.1186/gb-2014-15-11-502)
  • Mutant phenotypes: standardized Tn-seq compendium MtbTnDB (Jinich et al. 2025, doi:10.1111/mmi.15370), aggregating many primary Tn-seq studies across conditions
  • Physico-chemical properties: ExPASy ProtParam method via Biopython (Gasteiger et al. 2005), computed from the MTBC0 sequence
  • Predicted localisation: DeepTMHMM (Hallgren et al. 2022, doi:10.1101/2022.04.08.487609) for transmembrane topology and signal peptide
  • Primary literature: none located yet; annotation rests on the domain/homology sources above.

Ancestral MTBC0 protein sequence

>|Rv2322c|rocD1
MTNLADATQATMALVERHAAHNYSPLPVVAASAEGAWIADIDGLRYLDWLAAYSAVNLGHRNPASTATAHAQVDTVTLLNRALHADRLGPLGAALAQLCGKDVVLPMNSDAEAVESGLRVARKWGADVNGLPAGRHDIILANNNFHGHTSSVVSFSSDPAAGSGVEPSTPGLRSVPFGDAAAPAQTIDDNTVADLLEPIPGQAGIIVPADDYLPAASSTTC