Escherichia coli K-12 substr. MG1655 Enzyme: oxepin-CoA hydrolase/3-oxo-5,6-dehydrosuberyl-CoA semialdehyde dehydrogenase

Gene: paaZ Accession Numbers: G6708 (EcoCyc), b1387, ECK1384

Synonyms: ydbN, maoC

Regulation Summary Diagram: ?

Regulation summary diagram for paaZ

PaaZ (oxepin-CoA hydrolase/3-oxo-5,6-dehydrosuberyl-CoA semialdehyde dehydrogenase) is a two-domain enzyme that catalyzes the two-step conversion of 2-oxepin-2(3H)-ylideneacetyl-CoA to 3-oxo-5,6-didehydrosuberyl-CoA in phenylacetate catabolism. The PaaZ protein consists of an N-terminal NADP-dependent aldehyde dehydrogenase domain and a C-terminal MaoC-like (R)-specific enoyl-CoA hydratase domain [Teufel10, Teufel11]. The specific activity of the enzyme for the overall reaction is ~20 µM min-1 mg-1 protein [Teufel10].

3-oxo-5,6-dehydrosuberyl-CoA semialdehyde is a labile intermediate and undergoes spontaneous conversion to 2-hydroxycyclohepta-1,4,6-triene-1-carboxyl-CoA through a Knoevenagel-type condensation [Teufel11].

PaaZ exhibits enoyl-CoA hydratase activity utilizing crotonyl-CoA as a substrate. In a fadB mutant, PaaZ produces (R)-3-hydroxyacyl-CoA for polyhydroxyalkanoate biosynthesis by exogenous Pseudomonas medium-chain-length polyhydroxyalkanoate synthase [Park03].

A paaZ mutant exhibits a defect in utilization of phenylacetate as a source of carbon [Ismail03].

PaaZ: "phenylacetic acid degradation" [Ferrandez98]

Map Position: [1,449,621 <- 1,451,666] (31.24 centisomes, 112°)
Length: 2046 bp / 681 aa

Molecular Weight of Polypeptide: 73.003 kD (from nucleotide sequence)

Unification Links: ASAP:ABE-0004644 , EchoBASE:EB3498 , EcoGene:EG13735 , EcoliWiki:b1387 , ModBase:P77455 , OU-Microarray:b1387 , PortEco:maoC , PR:PRO_000023164 , Pride:P77455 , Protein Model Portal:P77455 , RefSeq:NP_415905 , RegulonDB:G6708 , SMR:P77455 , String:511145.b1387 , Swiss-Model:P77455 , UniProt:P77455

Relationship Links: InterPro:IN-FAMILY:IPR002539 , InterPro:IN-FAMILY:IPR011966 , InterPro:IN-FAMILY:IPR015590 , InterPro:IN-FAMILY:IPR016161 , InterPro:IN-FAMILY:IPR016162 , InterPro:IN-FAMILY:IPR016163 , InterPro:IN-FAMILY:IPR029069 , Panther:IN-FAMILY:PTHR11699:SF12 , Pfam:IN-FAMILY:PF00171 , Pfam:IN-FAMILY:PF01575 , Prosite:IN-FAMILY:PS00070 , Prosite:IN-FAMILY:PS00687

In Paralogous Gene Group: 95 (14 members)

Gene-Reaction Schematic: ?

Gene-Reaction Schematic

Genetic Regulation Schematic: ?

Genetic regulation schematic for paaZ

GO Terms:

Biological Process: GO:0010124 - phenylacetate catabolic process Inferred from experiment Inferred by computational analysis [UniProtGOA12, Ferrandez98, Ismail03]
GO:0008152 - metabolic process Inferred by computational analysis [UniProtGOA11]
GO:0055114 - oxidation-reduction process Inferred by computational analysis [UniProtGOA11, GOA01]
Molecular Function: GO:0004300 - enoyl-CoA hydratase activity Inferred from experiment [Park03]
GO:0016726 - oxidoreductase activity, acting on CH or CH2 groups, NAD or NADP as acceptor Inferred from experiment [Teufel11]
GO:0016803 - ether hydrolase activity Inferred from experiment [Teufel11]
GO:0016823 - hydrolase activity, acting on acid carbon-carbon bonds, in ketonic substances Inferred from experiment [Teufel11]
GO:0003824 - catalytic activity Inferred by computational analysis [UniProtGOA11]
GO:0004029 - aldehyde dehydrogenase (NAD) activity Inferred by computational analysis [Gaudet10]
GO:0016491 - oxidoreductase activity Inferred by computational analysis [UniProtGOA11, GOA01]
GO:0016620 - oxidoreductase activity, acting on the aldehyde or oxo group of donors, NAD or NADP as acceptor Inferred by computational analysis [GOA01]
GO:0016787 - hydrolase activity Inferred by computational analysis [UniProtGOA11]
GO:0016829 - lyase activity Inferred by computational analysis [UniProtGOA11]

MultiFun Terms: metabolism carbon utilization carbon compounds

Essentiality data for paaZ 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 ? 11-Jul-2014 by Keseler I , SRI International

Enzymatic reaction of: oxepin-CoA hydrolase

EC Number:

2-oxepin-2(3H)-ylideneacetyl-CoA + H2O <=> 3-oxo-5,6-didehydrosuberyl-CoA semialdehyde

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: superpathway of phenylethylamine degradation , phenylacetate degradation I (aerobic)

Imported from MetaCyc 30-Sep-2011 by Caspi R , SRI International

Inhibitors (Unknown Mechanism): 2-hydroxycyclohepta-1,4,6-triene-1-carboxyl-CoA [Teufel11]

Kinetic Parameters:

Km (μM)

pH(opt): 8 [Teufel11]

Enzymatic reaction of: 3-oxo-5,6-dehydrosuberyl-CoA semialdehyde dehydrogenase

EC Number:

3-oxo-5,6-didehydrosuberyl-CoA semialdehyde + NADP+ + H2O <=> 3-oxo-5,6-didehydrosuberyl-CoA + NADPH + 2 H+

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.

Alternative Substrates for NADP+: NAD+ [Teufel11 ]

In Pathways: superpathway of phenylethylamine degradation , phenylacetate degradation I (aerobic)

Imported from MetaCyc 30-Sep-2011 by Caspi R , SRI International

NAD+ can be utilized at 50% of the efficiency with NADP+ [Teufel11].

Kinetic Parameters:

Km (μM)

pH(opt): 8 [Teufel11]

Enzymatic reaction of: crotonyl-CoA hydratase (oxepin-CoA hydrolase/3-oxo-5,6-dehydrosuberyl-CoA semialdehyde dehydrogenase)

EC Number:

(R)-3-hydroxybutanoyl-CoA <=> crotonyl-CoA + H2O

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

Reversibility of this reaction is unspecified.

Among the substrates tested, significant activity was only observed with crotonyl-CoA [Teufel11]. The specific activities measured by [Park03] and [Teufel11] differ significantly.

Sequence Features

Protein sequence of oxepin-CoA hydrolase/3-oxo-5,6-dehydrosuberyl-CoA semialdehyde dehydrogenase with features indicated

Feature Class Location Citations Comment
Protein-Segment 1 -> 333
UniProt: Aldehyde dehydrogenase; Sequence Annotation Type: region of interest.
Extrinsic-Sequence-Variant 143
UniProt: In strain: W..
Mutagenesis-Variant 256
[Teufel11, UniProt12a]
UniProt: Catalyzes the formation of 3-oxo- 5,6-dehydrosuberyl-CoA semialdehyde instead of 3-oxo-5,6-dehydrosuberyl-CoA.
Active-Site 256
UniProt: Non-Experimental Qualifier: by similarity;
Active-Site 295
UniProt: Non-Experimental Qualifier: by similarity;
Extrinsic-Sequence-Variant 440
UniProt: In strain: W..
Conserved-Region 537 -> 648
UniProt: MaoC-like.
Extrinsic-Sequence-Variant 611
UniProt: In strain: W..

Gene Local Context (not to scale): ?

Gene local context diagram

Transcription Units:

Transcription-unit diagram

Transcription-unit diagram


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

Ferrandez98: Ferrandez A, Minambres B, Garcia B, Olivera ER, Luengo JM, Garcia JL, Diaz E (1998). "Catabolism of phenylacetic acid in Escherichia coli. Characterization of a new aerobic hybrid pathway." J Biol Chem 1998;273(40);25974-86. PMID: 9748275

Gaudet10: Gaudet P, Livstone M, Thomas P (2010). "Annotation inferences using phylogenetic trees." PMID: 19578431

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."

Ismail03: Ismail W, El-Said Mohamed M, Wanner BL, Datsenko KA, Eisenreich W, Rohdich F, Bacher A, Fuchs G (2003). "Functional genomics by NMR spectroscopy. Phenylacetate catabolism in Escherichia coli." Eur J Biochem 270(14);3047-54. PMID: 12846838

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

Park03: Park SJ, Lee SY (2003). "Identification and characterization of a new enoyl coenzyme A hydratase involved in biosynthesis of medium-chain-length polyhydroxyalkanoates in recombinant Escherichia coli." J Bacteriol 185(18);5391-7. PMID: 12949091

Teufel10: Teufel R, Mascaraque V, Ismail W, Voss M, Perera J, Eisenreich W, Haehnel W, Fuchs G (2010). "Bacterial phenylalanine and phenylacetate catabolic pathway revealed." Proc Natl Acad Sci U S A 107(32):14390-5. PMID: 20660314

Teufel11: Teufel R, Gantert C, Voss M, Eisenreich W, Haehnel W, Fuchs G (2011). "Studies on the mechanism of ring hydrolysis in phenylacetate degradation: a metabolic branching point." J Biol Chem 286(13);11021-34. PMID: 21296885

UniProt10: UniProt Consortium (2010). "UniProt version 2010-07 released on 2010-06-15 00:00:00." Database.

UniProt11: UniProt Consortium (2011). "UniProt version 2011-06 released on 2011-06-30 00:00:00." Database.

UniProt12a: UniProt Consortium (2012). "UniProt version 2012-09 released on 2012-09-12 00:00:00." Database.

UniProt15: UniProt Consortium (2015). "UniProt version 2015-01 released on 2015-01-16 00:00:00." Database.

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

UniProtGOA12: UniProt-GOA (2012). "Gene Ontology annotation based on UniPathway vocabulary mapping."

Other References Related to Gene Regulation

Ferrandez00: Ferrandez A, Garcia JL, Diaz E (2000). "Transcriptional regulation of the divergent paa catabolic operons for phenylacetic acid degradation in Escherichia coli." J Biol Chem 275(16);12214-22. PMID: 10766858

Kim04a: Kim HS, Kang TS, Hyun JS, Kang HS (2004). "Regulation of penicillin G acylase gene expression in Escherichia coli by repressor PaaX and the cAMP-cAMP receptor protein complex." J Biol Chem 279(32);33253-62. PMID: 15159386

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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 Sat Oct 10, 2015, biocyc12.