TB Genome Annotation Portal

Rv2200c (ctaC)

• Current annotations:
  • TBCAP: (community-based annotations - see table at bottom of page)
  • TBDB: cytochrome c oxidase subunit 2
  • REFSEQ: transmembrane cytochrome C oxidase subunit II CtaC
  • PATRIC: Cytochrome c oxidase polypeptide II (EC 1.9.3.1)
  • TUBERCULIST: Probable transmembrane cytochrome C oxidase (subunit II) CtaC
  • NCBI: Probable transmembrane cytochrome C oxidase (subunit II) CtaC
  • updated information (H37Rv4):
    • gene name: ctaC
    • function:
    • reference:
• Coordinates in H37Rv: 2463660 - 2464751
• Gene length: 1092 bp (with stop codon), 363 aa (without stop codon)
• Operon:


• Trans-membrane region:
  
• Role: I.B.6.a - aerobic
• GO terms:
  • GO:1902600 - proton transmembrane transport (Uniprot)
  • GO:0070469 - respiratory chain (Uniprot)
  • GO:0055114 - oxidation-reduction process (Uniprot)
  • GO:0046872 - metal ion binding (Uniprot)
  • GO:0044121 - growth of symbiont in host organelle (Uniprot)
  • GO:0042773 - ATP synthesis coupled electron transport (Uniprot)
  • GO:0040007 - growth (Uniprot)
  • GO:0016491 - oxidoreductase activity (Uniprot)
  • GO:0016021 - integral component of membrane (Uniprot)
  • GO:0016020 - membrane (Uniprot)
  • GO:0009319 - cytochrome o ubiquinol oxidase complex (Uniprot)
  • GO:0005887 - integral component of plasma membrane (Uniprot)
  • GO:0005886 - plasma membrane (Uniprot)
  • GO:0005576 - extracellular region (Uniprot)
  • GO:0005507 - copper ion binding (Uniprot)
  • GO:0004129 - cytochrome-c oxidase activity (Uniprot)
• Reaction(s) (based on iSM810 metabolic model):
  • 0.5 O2[c] + 2 HEME_FE2[c] -> 6 H[c] + 2 HEME_FE3[c]
  • MKH2[c] + 2 HEME_FE3[c] <=> MK[c] + 2 HEME_FE2[c]
• Gene Expression Profile (Transcriptional Responses to Drugs; Boshoff et al, 2004)
• Gene Modules extracted from cluster analysis of 249 transcriptomic datasets using ICA
• Orthologs among selected mycobacteria
• Protein structure:
• Search for Latest Homologs in PDB
• Top 10 Homologs in PDB (as of Apr 2026):
  

  PDB	aa ident	species	PDB title
  8HCR	99%	Mycobacterium tuberculosis variant bovis BCG	Cryo-EM structure of the Mycobacterium tuberculosis cytochrome bcc:aa3 supercomplex and a novel inhibitor targeting subunit cytochrome cI
  9DM1	77%	Mycolicibacterium smegmatis MC2 155	Mycobacterial supercomplex malate:quinone oxidoreductase assembly
  7RH7	77%	Mycolicibacterium smegmatis MC2 155	Mycobacterial CIII2CIV2 supercomplex, Telacebec (Q203) bound
  7RH6	77%	Mycolicibacterium smegmatis (strain ATCC 700084 / mc(2)155)	Mycobacterial CIII2CIV2 supercomplex, inhibitor free, -Lpqe cyt cc open
  9QEF	75%	Mycolicibacterium smegmatis	Respiratory supercomplex from Mycobacterium smegmatis with decylubiquinone
  9GY6	75%	Mycolicibacterium smegmatis MC2 155	Mycobacterial cytochrome bc1:aa3 with inhibitor
  9FU0	75%	Mycolicibacterium smegmatis	CIII2/CIV respiratory chain supercomplex from Mycobacterium smegmatis
  9FTZ	75%	Mycolicibacterium smegmatis	CIII2/CIV respiratory supercomplex from Mycobacterium smegmatis with lansoprazole sulfide
  8OVD	75%	Mycolicibacterium smegmatis	Respiratory supercomplex (III2-IV2) from Mycobacterium smegmatis
  8OVC	75%	Mycolicibacterium smegmatis	Respiratory supercomplex (III2-IV2) from Mycobacterium smegmatis

• Links to additional information on ctaC:
  • TBDB (updated)
  • Phyre2 structure prediction, model: final.casp.pdb (from Mao et al, 2013)
  • UniProt
  • AlphaFold model
  • Vulnerability = -8.533 (from Jeremy Rock's lab)
  • KEGG - nucleotide and amino acid sequences of gene
  • Mycobrowser
  • PATRIC
  • BioCyc
  • Systems Biology

Amino Acid Sequence

VTPRGPGRLQRLSQCRPQRGSGGPARGLRQLALAAMLGALAVTVSGCSWSEALGIGWPEGITPEAHLNRELWIGAVIASLAVGVIVWGLIFWSAVFHRKK
NTDTELPRQFGYNMPLELVLTVIPFLIISVLFYFTVVVQEKMLQIAKDPEVVIDITSFQWNWKFGYQRVNFKDGTLTYDGADPERKRAMVSKPEGKDKYG
EELVGPVRGLNTEDRTYLNFDKVETLGTSTEIPVLVLPSGKRIEFQMASADVIHAFWVPEFLFKRDVMPNPVANNSVNVFQIEEITKTGAFVGHCAEMCG
TYHSMMNFEVRVVTPNDFKAYLQQRIDGKTNAEALRAINQPPLAVTTHPFDTRRGELAPQPVG

Additional Information

Analysis of Positive Selection in Clinical Isolates *new*

• data from Culviner et al (2025) (55,259 Mtb clinical isolates)
  • overall pN/pS for Rv2200c: 0.617825865
  • lineage-specific pN/pS in L1: 0.53563802
  • lineage-specific pN/pS in L2: 0.642765624
  • lineage-specific pN/pS in L3: 1.047469906
  • lineage-specific pN/pS in L4: 0.55139208

• Analysis of dN/dS (omega) in a global collection of 10k Mtb clinical isolates using GenomegaMap (Window model)
• clinical isolates collection: global set of 10,626 Mtb genomes
• In the omega plots, the black line shows the mean estimate of omega (dN/dS) at each codon, and the blue lines are the bounds for the 95% credible interval (95%CI, from MCMC sampling).
• A gene is under significant positive selection if the lower-bound of the 95%CI of omega (lower blue line) exceeds 1.0 at any codon.

	global set of 10,626 Mtb clinical isolates
under significant positive selection?	NO
omega peak height (95%CI lower bound)	1.68 (0.77)
codons under selection
omega plots
genetic variants*	link