Escherichia coli K-12 substr. MG1655 Enzyme: molybdopterin biosynthesis protein A

Gene: moaA Accession Numbers: EG11595 (EcoCyc), b0781, ECK0770

Synonyms: bisA, chlA, chlA1, narA

Regulation Summary Diagram: ?

Regulation summary diagram for moaA

Molybdenum and tungsten cofactors of all enzymes (except nitrogenase) that require one or the other for activity are present in an oxidized state as molybdate or tungstate ions that are chelated by the cis-dithiolene moiety of a molybdenum cofactor. The cofactor that predominates in E. coli is molybdopterin guanine dinucleotide.

Although much progress has been made in elucidating the biosynthetic pathways for molybdenum cofactors (see the [IobbiNivol13] review), some details remain to be determined. In the first segment 5'-GTP is converted in several steps that involve MoaA and MoaC to a sulfur-free pterin named precursor Z (cyclic pyranopterin phosphate); then in a subsequent series of reactions two sulfhydryl groups are added yielding molybdopterin with its cis-dithiolene moiety; finally molybdenum is inserted via chelation into the cis-dithiolene moiety and a guanyl group is added, yielding molybdopterin guanine dinucleotide.

Enzymes encoded by the moaABCDE, mobAB, mogA, and moeAB operons all participate in the synthesis of molybdopterin guanine dinucleotide. A mutational block in any of these proteins leads to a loss of function of all molybdenum enzymes. Proteins encoded by the moaABCDE operon participate in the first two segments of the biosynthetic pathway, the conversion of a guanosine derivative to precursor Z, and its conversion to molybdopterin.

E. coli MoaA is a member of the radical SAM superfamily [Sofia01]. Although both MoaA and MoaC are involved in the formation of precursor Z (cyclic pyranopterin phosphate), the role of MoaC remains unclear [Wuebbens00]. Using an E. coli strain overproducing MoaA and MoaC, precursor Z was produced, purified, and chemically characterized [SantamariaArauj04]. In earlier work, expression of genes moaABC in a moeA mutant resulted in the production of a product of precursor Z [Rieder98].

moaA, moeA and modC mutants are hypersensitive to the base analog 6-hydroxylaminopurine [Kozmin00, Burgis03, Kozmin07].

moaA, mog (mogA), moaB, moaE, modB, or modC deletion mutants lose the ability to reduce tellurite (tellurate), which can be restored by complementation. Although the E. coli tellurate reductase gene and its product remain uncharacterized, these data suggest that it involves a molybdoenzyme [Theisen13].

The molybdate-sensing transcription regulator ModE acts as an activator for six operons including the moaABCDE operon [Kurata13, Anderson00]. Studies suggest that the mRNA leader of moaA is posttranscriptionally regulated by both the molybdenum cofactor and CsrA [PattersonFortin13, Regulski08].

moaA shows differential codon adaptation, resulting in differential translation efficiency signatures, in thermophilic microbes. It was therefore predicted to play a role in the heat shock response. A moaA deletion mutant was shown to be more sensitive than wild-type specifically to heat shock, but not other stresses [Kri14].

Reviews: [IobbiNivol13, Layer05]

Gene Citations: [McNicholas97, Rivers93]

Locations: cytosol

Map Position: [816,267 -> 817,256] (17.59 centisomes, 63°)
Length: 990 bp / 329 aa

Molecular Weight of Polypeptide: 37.346 kD (from nucleotide sequence)

Unification Links: ASAP:ABE-0002669 , CGSC:922 , DIP:DIP-10228N , EchoBASE:EB1552 , EcoGene:EG11595 , EcoliWiki:b0781 , Mint:MINT-1229909 , ModBase:P30745 , OU-Microarray:b0781 , PortEco:moaA , PR:PRO_000023260 , Pride:P30745 , Protein Model Portal:P30745 , RefSeq:NP_415302 , RegulonDB:EG11595 , SMR:P30745 , String:511145.b0781 , UniProt:P30745

Relationship Links: InterPro:IN-FAMILY:IPR000385 , InterPro:IN-FAMILY:IPR006638 , InterPro:IN-FAMILY:IPR007197 , InterPro:IN-FAMILY:IPR010505 , InterPro:IN-FAMILY:IPR013483 , InterPro:IN-FAMILY:IPR013785 , Pfam:IN-FAMILY:PF04055 , Pfam:IN-FAMILY:PF06463 , Prosite:IN-FAMILY:PS01305 , Smart:IN-FAMILY:SM00729

In Paralogous Gene Group: 195 (3 members)

Gene-Reaction Schematic: ?

Gene-Reaction Schematic

Genetic Regulation Schematic: ?

Genetic regulation schematic for moaA

GO Terms:

Biological Process: GO:0009408 - response to heat Inferred from experiment [Kri14]
GO:0032324 - molybdopterin cofactor biosynthetic process Inferred from experiment [Johnson87a]
GO:0006777 - Mo-molybdopterin cofactor biosynthetic process Inferred by computational analysis [UniProtGOA11, GOA06, GOA01]
Molecular Function: GO:0061597 - cyclic pyranopterin monophosphate synthase activity Inferred from experiment Inferred by computational analysis [GOA01a, SantamariaArauj04]
GO:0000166 - nucleotide binding Inferred by computational analysis [UniProtGOA11]
GO:0003824 - catalytic activity Inferred by computational analysis [GOA01]
GO:0005525 - GTP binding Inferred by computational analysis [UniProtGOA11]
GO:0016829 - lyase activity Inferred by computational analysis [UniProtGOA11]
GO:0046872 - metal ion binding Inferred by computational analysis [UniProtGOA11, GOA01]
GO:0051536 - iron-sulfur cluster binding Inferred by computational analysis [UniProtGOA11, GOA01]
GO:0051539 - 4 iron, 4 sulfur cluster binding Inferred by computational analysis [UniProtGOA11, GOA01]
Cellular Component: GO:0005829 - cytosol Inferred by computational analysis [DiazMejia09]
GO:0019008 - molybdopterin synthase complex Inferred by computational analysis [GOA01]

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

Essentiality data for moaA 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 ? 12-Feb-2015 by Fulcher C , SRI International

Enzymatic reaction of: cyclic pyranopterin monophosphate synthase (molybdopterin biosynthesis protein A)

EC Number:

GTP <=> cyclic pyranopterin phosphate + diphosphate

The reaction direction shown, that is, A + B ↔ C + D versus C + D ↔ A + B, is in accordance with the Enzyme Commission system.

The reaction is favored in the direction shown.

In Pathways: molybdenum cofactor biosynthesis

Imported from MetaCyc 13-Sep-2011 by Caspi R , SRI International

Sequence Features

Protein sequence of molybdopterin biosynthesis protein A with features indicated

Feature Class Location Citations Comment
Amino-Acid-Sites-That-Bind 17
UniProt: GTP; Non-Experimental Qualifier: by similarity;
Metal-Binding-Site 24
UniProt: Iron-sulfur 1 (4Fe-4S-S-AdoMet); Non-Experimental Qualifier: by similarity;
Metal-Binding-Site 28
UniProt: Iron-sulfur 1 (4Fe-4S-S-AdoMet); Non-Experimental Qualifier: by similarity;
Amino-Acid-Sites-That-Bind 30
UniProt: S-adenosyl-L-methionine; Non-Experimental Qualifier: by similarity;
Metal-Binding-Site 31
UniProt: Iron-sulfur 1 (4Fe-4S-S-AdoMet); Non-Experimental Qualifier: by similarity;
Amino-Acid-Sites-That-Bind 68
UniProt: GTP; Non-Experimental Qualifier: by similarity;
Amino-Acid-Sites-That-Bind 72
UniProt: S-adenosyl-L-methionine; via carbonyl oxygen; Non-Experimental Qualifier: by similarity;
Amino-Acid-Sites-That-Bind 99
UniProt: GTP; Non-Experimental Qualifier: by similarity;
Amino-Acid-Sites-That-Bind 123
UniProt: S-adenosyl-L-methionine; Non-Experimental Qualifier: by similarity;
Amino-Acid-Sites-That-Bind 160
UniProt: GTP; Non-Experimental Qualifier: by similarity;
Amino-Acid-Sites-That-Bind 194
UniProt: S-adenosyl-L-methionine; via amide nitrogen and carbonyl oxygen; Non-Experimental Qualifier: by similarity;
Metal-Binding-Site 257
UniProt: Iron-sulfur 2 (4Fe-4S-substrate); Non-Experimental Qualifier: by similarity;
Metal-Binding-Site 260
UniProt: Iron-sulfur 2 (4Fe-4S-substrate); Non-Experimental Qualifier: by similarity;
Protein-Segment 262 -> 264
UniProt: GTP binding; Sequence Annotation Type: region of interest; Non-Experimental Qualifier: by similarity;
Metal-Binding-Site 274
UniProt: Iron-sulfur 2 (4Fe-4S-substrate); Non-Experimental Qualifier: by similarity;

Gene Local Context (not to scale): ?

Gene local context diagram

Transcription Units:

Transcription-unit diagram

Transcription-unit diagram

Transcription-unit diagram


10/20/97 Gene b0781 from Blattner lab Genbank (v. M52) entry merged into EcoCyc gene EG11595; confirmed by SwissProt match.


Anderson00: Anderson LA, McNairn E, Lubke T, Pau RN, Boxer DH, Leubke T (2000). "ModE-dependent molybdate regulation of the molybdenum cofactor operon moa in Escherichia coli." J Bacteriol 2000;182(24);7035-43. PMID: 11092866

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

Burgis03: Burgis NE, Brucker JJ, Cunningham RP (2003). "Repair system for noncanonical purines in Escherichia coli." J Bacteriol 185(10);3101-10. PMID: 12730170

DiazMejia09: Diaz-Mejia JJ, Babu M, Emili A (2009). "Computational and experimental approaches to chart the Escherichia coli cell-envelope-associated proteome and interactome." FEMS Microbiol Rev 33(1);66-97. PMID: 19054114

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, DDB, FB, MGI, ZFIN (2001). "Gene Ontology annotation through association of InterPro records with GO terms."

GOA01a: GOA, MGI (2001). "Gene Ontology annotation based on Enzyme Commission mapping." Genomics 74;121-128.

GOA06: GOA, SIB (2006). "Electronic Gene Ontology annotations created by transferring manual GO annotations between orthologous microbial proteins."

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

Johnson87a: Johnson ME, Rajagopalan KV (1987). "Involvement of chlA, E, M, and N loci in Escherichia coli molybdopterin biosynthesis." J Bacteriol 169(1);117-25. PMID: 2947896

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

Kozmin00: Kozmin SG, Pavlov YI, Dunn RL, Schaaper RM (2000). "Hypersensitivity of Escherichia coli Delta(uvrB-bio) mutants to 6-hydroxylaminopurine and other base analogs is due to a defect in molybdenum cofactor biosynthesis." J Bacteriol 182(12);3361-7. PMID: 10852865

Kozmin07: Kozmin SG, Schaaper RM (2007). "Molybdenum cofactor-dependent resistance to N-hydroxylated base analogs in Escherichia coli is independent of MobA function." Mutat Res 619(1-2);9-15. PMID: 17349664

Kri14: Krisko A, Copi T, Gabaldon T, Lehner B, Supek F (2014). "Inferring gene function from evolutionary change in signatures of translation efficiency." Genome Biol 15(3);R44. PMID: 24580753

Kurata13: Kurata T, Katayama A, Hiramatsu M, Kiguchi Y, Takeuchi M, Watanabe T, Ogasawara H, Ishihama A, Yamamoto K (2013). "Identification of the set of genes, including nonannotated morA, under the direct control of ModE in Escherichia coli." J Bacteriol 195(19);4496-505. PMID: 23913318

Layer05: Layer G, Kervio E, Morlock G, Heinz DW, Jahn D, Retey J, Schubert WD (2005). "Structural and functional comparison of HemN to other radical SAM enzymes." Biol Chem 386(10);971-80. PMID: 16218869

McNicholas97: McNicholas PM, Rech SA, Gunsalus RP (1997). "Characterization of the ModE DNA-binding sites in the control regions of modABCD and moaABCDE of Escherichia coli." Mol Microbiol 1997;23(3);515-24. PMID: 9044285

PattersonFortin13: Patterson-Fortin LM, Vakulskas CA, Yakhnin H, Babitzke P, Romeo T (2013). "Dual posttranscriptional regulation via a cofactor-responsive mRNA leader." J Mol Biol 425(19);3662-77. PMID: 23274138

Regulski08: Regulski EE, Moy RH, Weinberg Z, Barrick JE, Yao Z, Ruzzo WL, Breaker RR (2008). "A widespread riboswitch candidate that controls bacterial genes involved in molybdenum cofactor and tungsten cofactor metabolism." Mol Microbiol 68(4);918-32. PMID: 18363797

Rieder98: Rieder C, Eisenreich W, O'Brien J, Richter G, Gotze E, Boyle P, Blanchard S, Bacher A, Simon H (1998). "Rearrangement reactions in the biosynthesis of molybdopterin--an NMR study with multiply 13C/15N labelled precursors." Eur J Biochem 255(1);24-36. PMID: 9692897

Rivers93: Rivers SL, McNairn E, Blasco F, Giordano G, Boxer DH (1993). "Molecular genetic analysis of the moa operon of Escherichia coli K-12 required for molybdenum cofactor biosynthesis." Mol Microbiol 1993;8(6);1071-81. PMID: 8361352

SantamariaArauj04: Santamaria-Araujo JA, Fischer B, Otte T, Nimtz M, Mendel RR, Wray V, Schwarz G (2004). "The tetrahydropyranopterin structure of the sulfur-free and metal-free molybdenum cofactor precursor." J Biol Chem 279(16);15994-9. PMID: 14761975

Sofia01: Sofia HJ, Chen G, Hetzler BG, Reyes-Spindola JF, Miller NE (2001). "Radical SAM, a novel protein superfamily linking unresolved steps in familiar biosynthetic pathways with radical mechanisms: functional characterization using new analysis and information visualization methods." Nucleic Acids Res 29(5);1097-106. PMID: 11222759

Theisen13: Theisen J, Zylstra GJ, Yee N (2013). "Genetic evidence for a molybdopterin-containing tellurate reductase." Appl Environ Microbiol 79(10);3171-5. PMID: 23475618

UniProt10a: UniProt Consortium (2010). "UniProt version 2010-07 released on 2010-06-15 00:00:00." Database.

UniProtGOA11: UniProt-GOA (2011). "Gene Ontology annotation based on manual assignment of UniProtKB keywords in UniProtKB/Swiss-Prot entries."

Wuebbens00: Wuebbens MM, Liu MT, Rajagopalan K, Schindelin H (2000). "Insights into molybdenum cofactor deficiency provided by the crystal structure of the molybdenum cofactor biosynthesis protein MoaC." Structure Fold Des 8(7);709-18. PMID: 10903949

Other References Related to Gene Regulation

Yamamoto05a: Yamamoto K, Ishihama A (2005). "Transcriptional response of Escherichia coli to external copper." Mol Microbiol 56(1);215-27. PMID: 15773991

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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 Wed Oct 7, 2015, biocyc14.