|Gene:||malY||Accession Numbers: EG10564 (MetaCyc), b1622, ECK1617|
Species: Escherichia coli K-12 substr. MG1655
MalY acts as a negative regulator of the maltose regulon by interacting directly with the MalT transcriptional activator and competing with the inducer maltotriose [Schreiber00, Clausen00]. Mutations that reduce MalY's repressor activity map to regions away from the enzyme active site [Clausen00]. Mutations in MalT have differential effects on its sensitivity to Aes, MalY and MalK, which inhibit the activator in similar, yet distinct, ways [Joly02, Schlegel02, Joly04].
MalY belongs to a family of aminotransferases [Mehta93] and catalyzes the carbon-sulfur bond cleavage (β C-S lyase) of cystathionine [Zdych95]. The cystathionase activity of MalY is not required for its regulatory function [Zdych95]. The physiological substrate is unknown [Clausen00]. An in-gel staining assay showed that MalY also has cysteine desulfhydrase (CD) activity. A quintuple ΔmetC tnaA cysK cysM malY mutant contains significantly reduced CD activity [Awano05].
|Map Position: [1,698,981 -> 1,700,153]|
Molecular Weight of Polypeptide: 43.642 kD (from nucleotide sequence), 42.0 kD (experimental) [Reidl91 ]
Molecular Weight of Multimer: 90.0 kD (experimental) [Bertoldi05]
Unification Links: ASAP:ABE-0005432 , CGSC:32257 , DIP:DIP-10151N , EchoBASE:EB0559 , EcoGene:EG10564 , EcoliWiki:b1622 , ModBase:P23256 , OU-Microarray:b1622 , PortEco:malY , PR:PRO_000023157 , Pride:P23256 , Protein Model Portal:P23256 , RefSeq:NP_416139 , RegulonDB:EG10564 , SMR:P23256 , String:511145.b1622 , UniProt:P23256
Relationship Links: InterPro:IN-FAMILY:IPR004839 , InterPro:IN-FAMILY:IPR015421 , InterPro:IN-FAMILY:IPR015422 , InterPro:IN-FAMILY:IPR015424 , InterPro:IN-FAMILY:IPR027619 , PDB:Structure:1D2F , Pfam:IN-FAMILY:PF00155 , Prosite:IN-FAMILY:PS00599
|Biological Process:||GO:0043433 - negative regulation of sequence-specific DNA binding transcription factor activity
GO:0006351 - transcription, DNA-templated [UniProtGOA11]
GO:0006355 - regulation of transcription, DNA-templated [UniProtGOA11]
GO:0008652 - cellular amino acid biosynthetic process [UniProtGOA11]
GO:0009058 - biosynthetic process [GOA01]
GO:0009086 - methionine biosynthetic process [UniProtGOA11]
|Molecular Function:||GO:0004121 - cystathionine beta-lyase activity
GO:0005515 - protein binding [Clausen00]
GO:0030170 - pyridoxal phosphate binding [GOA01, Zdych95, Clausen00]
GO:0042803 - protein homodimerization activity [Bertoldi05]
GO:0080146 - L-cysteine desulfhydrase activity [Awano05]
GO:0003824 - catalytic activity [GOA01]
GO:0016829 - lyase activity [UniProtGOA11]
|Cellular Component:||GO:0005829 - cytosol [DiazMejia09]|
|MultiFun Terms:||metabolism → carbon utilization → carbon compounds|
|regulation → genetic unit regulated → operon|
|regulation → type of regulation → posttranscriptional → inhibition / activation of enzymes|
Enzymatic reaction of: cystathionine β-lyase (bifunctional β-cystathionase, PLP-dependent and regulator of maltose regulon)
Synonyms: β-cystathionase, cystathionase
The reaction direction shown, that is, A + B ↔ C + D versus C + D ↔ A + B, is in accordance with the direction in which it was curated.
The reaction is physiologically favored in the direction shown.
In Pathways: superpathway of S-adenosyl-L-methionine biosynthesis , aspartate superpathway , superpathway of L-lysine, L-threonine and L-methionine biosynthesis I , superpathway of L-methionine biosynthesis (transsulfuration) , L-homoserine and L-methionine biosynthesis , L-methionine biosynthesis I
pH(opt): 8.2 [Zdych95]
Enzymatic reaction of: L-cysteine desulfhydrase (bifunctional β-cystathionase, PLP-dependent and regulator of maltose regulon)
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: L-cysteine degradation II
10/20/97 Gene b1622 from Blattner lab Genbank (v. M52) entry merged into EcoCyc gene EG10564; confirmed by SwissProt match.
Awano05: Awano N, Wada M, Mori H, Nakamori S, Takagi H (2005). "Identification and functional analysis of Escherichia coli cysteine desulfhydrases." Appl Environ Microbiol 71(7);4149-52. PMID: 16000837
Bertoldi05: Bertoldi M, Cellini B, Laurents DV, Borri Voltattorni C (2005). "Folding pathway of the pyridoxal 5'-phosphate C-S lyase MalY from Escherichia coli." Biochem J 389(Pt 3);885-98. PMID: 15823094
Clausen00: Clausen T, Schlegel A, Peist R, Schneider E, Steegborn C, Chang YS, Haase A, Bourenkov GP, Bartunik HD, Boos W (2000). "X-ray structure of MalY from Escherichia coli: a pyridoxal 5'-phosphate-dependent enzyme acting as a modulator in mal gene expression." EMBO J 19(5);831-42. PMID: 10698925
DAmbrosio08: D'Ambrosio C, Mandrich L, Rossi M, Scaloni A, Manco G (2008). "A proteomic approach to study Escherichia coli. Acetyl esterase interactors unveil a sequence motif involved in protein-protein interaction." Protein Pept Lett 15(4);333-40. PMID: 18473943
Decker98: Decker K, Plumbridge J, Boos W (1998). "Negative transcriptional regulation of a positive regulator: the expression of malT, encoding the transcriptional activator of the maltose regulon of Escherichia coli, is negatively controlled by Mlc." Mol Microbiol 27(2);381-90. PMID: 9484893
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
Joly02: Joly N, Danot O, Schlegel A, Boos W, Richet E (2002). "The Aes protein directly controls the activity of MalT, the central transcriptional activator of the Escherichia coli maltose regulon." J Biol Chem 277(19);16606-13. PMID: 11867639
Joly04: Joly N, Bohm A, Boos W, Richet E (2004). "MalK, the ATP-binding cassette component of the Escherichia coli maltodextrin transporter, inhibits the transcriptional activator malt by antagonizing inducer binding." J Biol Chem 279(32);33123-30. PMID: 15180985
Mehta93: Mehta PK, Christen P (1993). "Homology of pyridoxal-5'-phosphate-dependent aminotransferases with the cobC (cobalamin synthesis), nifS (nitrogen fixation), pabC (p-aminobenzoate synthesis) and malY (abolishing endogenous induction of the maltose system) gene products." Eur J Biochem 211(1-2);373-6. PMID: 8425548
Reidl91: Reidl J, Boos W (1991). "The malX malY operon of Escherichia coli encodes a novel enzyme II of the phosphotransferase system recognizing glucose and maltose and an enzyme abolishing the endogenous induction of the maltose system." J Bacteriol 173(15);4862-76. PMID: 1856179
Schlegel02: Schlegel A, Danot O, Richet E, Ferenci T, Boos W (2002). "The N terminus of the Escherichia coli transcription activator MalT is the domain of interaction with MalY." J Bacteriol 184(11);3069-77. PMID: 12003949
Schreiber00: Schreiber V, Steegborn C, Clausen T, Boos W, Richet E (2000). "A new mechanism for the control of a prokaryotic transcriptional regulator: antagonistic binding of positive and negative effectors." Mol Microbiol 35(4);765-76. PMID: 10692154
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