Escherichia coli K-12 substr. MG1655 Enzyme: molybdenum cofactor cytidylyltransferase

Gene: mocA Accession Numbers: G7496 (EcoCyc), b2877, ECK2873

Synonyms: ygfJ

Regulation Summary Diagram: ?

Regulation summary diagram for mocA

MocA is a molybdenum cofactor cytidylyltransferase belonging to the NTP transferase superfamily of proteins. The enzyme catalyzes the transfer of a CMP moiety from CTP to Mo-molybdopterin, forming MCD [Neumann09]. The specificity of MocA for CTP was also investigated, showing that the N-terminal domain determines nucleotide recognition and binding. The C-terminal domain is responsible for interacting with the specific acceptor protein PaoD [Neumann11].

A mocA mutant contains inactive aldehyde dehydrogenase lacking molybdenum and is thus unable to grow on medium containing cinnamaldehyde [Neumann09].

Review: [IobbiNivol13]

Map Position: [3,013,182 -> 3,013,760] (64.94 centisomes, 234°)
Length: 579 bp / 192 aa

Molecular Weight of Polypeptide: 21.514 kD (from nucleotide sequence)

Unification Links: ASAP:ABE-0009447 , EchoBASE:EB2872 , EcoGene:EG13060 , EcoliWiki:b2877 , ModBase:Q46810 , OU-Microarray:b2877 , PortEco:mocA , Protein Model Portal:Q46810 , RefSeq:NP_417353 , RegulonDB:G7496 , SMR:Q46810 , String:511145.b2877 , UniProt:Q46810

Relationship Links: InterPro:IN-FAMILY:IPR017696 , InterPro:IN-FAMILY:IPR025877 , InterPro:IN-FAMILY:IPR029044 , Pfam:IN-FAMILY:PF12804

Gene-Reaction Schematic: ?

Gene-Reaction Schematic

GO Terms:

Biological Process: GO:0006777 - Mo-molybdopterin cofactor biosynthetic process Inferred from experiment Inferred by computational analysis [UniProtGOA11a, Neumann09]
GO:1902760 - Mo(VI)-molybdopterin cytosine dinucleotide biosynthetic process Inferred from experiment [Neumann09]
Molecular Function: GO:0000287 - magnesium ion binding Inferred from experiment [Neumann09]
GO:0005515 - protein binding Inferred from experiment [Neumann11]
GO:0061602 - molybdenum cofactor cytidylyltransferase activity Inferred from experiment Inferred by computational analysis [GOA01, Neumann09]
GO:0000166 - nucleotide binding Inferred by computational analysis [UniProtGOA11a]
GO:0016740 - transferase activity Inferred by computational analysis [UniProtGOA11a]
GO:0046872 - metal ion binding Inferred by computational analysis [UniProtGOA11a]

MultiFun Terms: metabolism biosynthesis of building blocks cofactors, small molecule carriers molybdenum

Essentiality data for mocA knockouts: ?

Growth Medium Growth? T (°C) O2 pH Osm/L Growth Observations
LB enriched Yes 37 Aerobic 6.95   Yes [Gerdes03, Comment 1]
LB Lennox Yes 37 Aerobic 7   Yes [Baba06, Comment 2]
M9 medium with 1% glycerol Yes 37 Aerobic 7.2 0.35 Yes [Joyce06, Comment 3]
MOPS medium with 0.4% glucose Yes 37 Aerobic 7.2 0.22 Yes [Baba06, Comment 2]

Last-Curated ? 14-Feb-2014 by Keseler I , SRI International

Enzymatic reaction of: molybdenum cofactor cytidylyltransferase

Synonyms: CTP:molybdopterin cytidylyltransferase

EC Number:

CTP + MoO2-molybdopterin cofactor + H+ <=> cytidylyl molybdenum cofactor + diphosphate

The reaction direction shown, that is, A + B ↔ C + D versus C + D ↔ A + B, is in accordance with the direction of enzyme catalysis.

The reaction is physiologically favored in the direction shown.

In Pathways: cytidylyl molybdenum cofactor biosynthesis

Cofactors or Prosthetic Groups: Mg2+ [Neumann09]

Kinetic Parameters:

Km (μM)
kcat (sec-1)
kcat/Km (sec-1 μM-1)
4.6, 3.4
0.003, 0.0062, 0.0062
6.5e-4, 0.0013, 0.0013, 8.8e-4, 0.0018, 0.0018
[Neumann09, BRENDA14]

Sequence Features

Protein sequence of molybdenum cofactor cytidylyltransferase with features indicated

Feature Class Location Citations Comment
Mutagenesis-Variant 9 -> 11
[Neumann11, UniProt12]
UniProt: 12-fold decrease in affinity for CTP and 3-fold decrease in catalytic activity. Displays a 3-fold decrease in activity with CTP and gains a low activity with GTP as substrate; when associated with 79-P--G-82.
Mutagenesis-Variant 79 -> 82
[Neumann11, UniProt12]
UniProt: 15-fold decrease in affinity for CTP and 1.5-fold decrease in catalytic activity. Displays a 3-fold decrease in activity with CTP and gains a low activity with GTP as substrate; when associated with 9-L--G-11.
Metal-Binding-Site 101
UniProt: Magnesium; Non-Experimental Qualifier: by similarity.

Gene Local Context (not to scale): ?

Gene local context diagram

Transcription Unit:

Transcription-unit diagram


Peter D. Karp on Thu Jan 16, 2003:
Predicted gene function revised as a result of E. coli genome reannotation by Serres et al. [Serres01 ].
Markus Krummenacker on Tue Oct 14, 1997:
Gene object created from Blattner lab Genbank (v. M52) entry.


Baba06: Baba T, Ara T, Hasegawa M, Takai Y, Okumura Y, Baba M, Datsenko KA, Tomita M, Wanner BL, Mori H (2006). "Construction of Escherichia coli K-12 in-frame, single-gene knockout mutants: the Keio collection." Mol Syst Biol 2;2006.0008. PMID: 16738554

BRENDA14: BRENDA team (2014). "Imported from BRENDA version existing on Aug 2014."

Gerdes03: Gerdes SY, Scholle MD, Campbell JW, Balazsi G, Ravasz E, Daugherty MD, Somera AL, Kyrpides NC, Anderson I, Gelfand MS, Bhattacharya A, Kapatral V, D'Souza M, Baev MV, Grechkin Y, Mseeh F, Fonstein MY, Overbeek R, Barabasi AL, Oltvai ZN, Osterman AL (2003). "Experimental determination and system level analysis of essential genes in Escherichia coli MG1655." J Bacteriol 185(19);5673-84. PMID: 13129938

GOA01: GOA, MGI (2001). "Gene Ontology annotation based on Enzyme Commission mapping." Genomics 74;121-128.

IobbiNivol13: Iobbi-Nivol C, Leimkuhler S (2013). "Molybdenum enzymes, their maturation and molybdenum cofactor biosynthesis in Escherichia coli." Biochim Biophys Acta 1827(8-9);1086-101. PMID: 23201473

Joyce06: Joyce AR, Reed JL, White A, Edwards R, Osterman A, Baba T, Mori H, Lesely SA, Palsson BO, Agarwalla S (2006). "Experimental and computational assessment of conditionally essential genes in Escherichia coli." J Bacteriol 188(23);8259-71. PMID: 17012394

Neumann09: Neumann M, Mittelstadt G, Seduk F, Iobbi-Nivol C, Leimkuhler S (2009). "MocA is a specific cytidylyl transferase involved in molybdopterin cytosine dinucleotide biosynthesis in Escherichia coli." J Biol Chem 284(33);21891-8. PMID: 19542235

Neumann11: Neumann M, Seduk F, Iobbi-Nivol C, Leimkuhler S (2011). "Molybdopterin dinucleotide biosynthesis in Escherichia coli: identification of amino acid residues of molybdopterin dinucleotide transferases that determine specificity for binding of guanine or cytosine nucleotides." J Biol Chem 286(2);1400-8. PMID: 21081498

Serres01: Serres MH, Gopal S, Nahum LA, Liang P, Gaasterland T, Riley M (2001). "A functional update of the Escherichia coli K-12 genome." Genome Biol 2(9);RESEARCH0035. PMID: 11574054

UniProt12: UniProt Consortium (2012). "UniProt version 2012-09 released on 2012-09-12 00:00:00." Database.

UniProtGOA11a: UniProt-GOA (2011). "Gene Ontology annotation based on manual assignment of UniProtKB keywords in UniProtKB/Swiss-Prot entries."

Report Errors or Provide Feedback
Please cite the following article in publications resulting from the use of EcoCyc: Nucleic Acids Research 41:D605-12 2013
Page generated by SRI International Pathway Tools version 19.0 on Tue Oct 13, 2015, biocyc12.