Escherichia coli K-12 substr. MG1655 Enzyme: serine acetyltransferase

Gene: cysE Accession Numbers: EG10187 (EcoCyc), b3607, ECK3597

Regulation Summary Diagram: ?

Regulation summary diagram for cysE

Component of: cysteine synthase complex (summary available)

Subunit composition of serine acetyltransferase = [CysE]6
         serine acetyltransferase monomer = CysE

Serine acetyltransferase carries out the first step in the pathway of cysteine biosynthesis, converting L-serine into O-acetyl-L-serine.

Serine acetyltransferase catalyzes the acetylation of L-serine to generate O-acetyl-L-serine [Kredich66, Denk87, Sirko88, Hindson03]. Cysteine strongly inhibits this activity by binding to the serine-binding site [Hindson03a, Pye04]. This inhibition depends on the protein's carboxy terminus, and has been localized to Met-256 specifically [Denk87, Nakamori98, Mino99, Takagi99, Mino00]. The carboxy-terminus is also required for formation of the complex with O-acetylserine sulhydrylase, as well as for destabilization of the serine acetyltransferase hexamer in cold temperatures [Mino99, Mino00]. The carboxy-terminus of wild-type serine acetyltransferase is protected from proteolysis in the complexed state [Mino01].

The reaction mechanism of serine acetyltransferase has been examined in detail [Hindson03, Hindson03a].

Although serine acetyltransferase was identified as a tetramer based on a 3.0 Å-resolution crystal structure, later structural studies indicated that it is actually a dimer of trimers [Wigley90, Hindson00]. A crystal structure to 2.2 Å resolution has confirmed this dimer of trimers arrangement [Pye04].

Mutants in cysE show increased biofilm formation. In these mutants, both cysteine and the extracellular signal O-acetylserine inhibit biofilm formation [Sturgill04].

Locations: cytosol

Map Position: [3,779,764 <- 3,780,585] (81.47 centisomes, 293°)
Length: 822 bp / 273 aa

Molecular Weight of Polypeptide: 29.317 kD (from nucleotide sequence), 33 kD (experimental) [Tei90 ]

pI: 6.45

Unification Links: ASAP:ABE-0011793 , CGSC:894 , DIP:DIP-9377N , EchoBASE:EB0184 , EcoGene:EG10187 , EcoliWiki:b3607 , ModBase:P0A9D4 , OU-Microarray:b3607 , PortEco:cysE , PR:PRO_000022377 , Pride:P0A9D4 , Protein Model Portal:P0A9D4 , RefSeq:NP_418064 , RegulonDB:EG10187 , SMR:P0A9D4 , String:511145.b3607 , UniProt:P0A9D4

Relationship Links: InterPro:IN-FAMILY:IPR001451 , InterPro:IN-FAMILY:IPR005881 , InterPro:IN-FAMILY:IPR010493 , InterPro:IN-FAMILY:IPR011004 , InterPro:IN-FAMILY:IPR018357 , PDB:Structure:1T3D , Pfam:IN-FAMILY:PF00132 , Pfam:IN-FAMILY:PF06426 , Prosite:IN-FAMILY:PS00101 , Smart:IN-FAMILY:SM00971

In Paralogous Gene Group: 11 (13 members)

Gene-Reaction Schematic: ?

Gene-Reaction Schematic

Genetic Regulation Schematic: ?

Genetic regulation schematic for cysE

GO Terms:

Biological Process: GO:0006535 - cysteine biosynthetic process from serine Inferred from experiment Inferred by computational analysis [GOA01a, Kredich66]
GO:0008652 - cellular amino acid biosynthetic process Inferred by computational analysis [UniProtGOA11a]
GO:0019344 - cysteine biosynthetic process Inferred by computational analysis [UniProtGOA12, UniProtGOA11a]
Molecular Function: GO:0009001 - serine O-acetyltransferase activity Inferred from experiment Inferred by computational analysis [GOA01, GOA01a, Kredich66]
GO:0016740 - transferase activity Inferred by computational analysis [UniProtGOA11a, GOA01a]
GO:0016746 - transferase activity, transferring acyl groups Inferred by computational analysis [UniProtGOA11a]
Cellular Component: GO:0005829 - cytosol Inferred from experiment Inferred by computational analysis [DiazMejia09, Ishihama08]
GO:0009333 - cysteine synthase complex Inferred from experiment [Mino00a]
GO:0005737 - cytoplasm Inferred by computational analysis [UniProtGOA11, UniProtGOA11a, GOA01a]

MultiFun Terms: metabolism biosynthesis of building blocks amino acids cysteine

Essentiality data for cysE knockouts: ?

Growth Medium Growth? T (°C) O2 pH Osm/L Growth Observations
LB Lennox Yes 37 Aerobic 7   Yes [Baba06, Comment 1]
M9 medium with 0.4% glucose No 37 Aerobic 7.2 0.27 No [Patrick07, Comment 2]
M9 medium with 1% glycerol No 37 Aerobic 7.2 0.35 No [Joyce06]
MOPS medium with 0.4% glucose Indeterminate 37 Aerobic 7.2 0.22 Yes [Baba06, Comment 1]
No [Feist07, Comment 3]

Last-Curated ? 22-Mar-2007 by Shearer A , SRI International

Enzymatic reaction of: serine acetyltransferase

Synonyms: serine-O-acetyltransferase, SAT, serine transacetylase, STA, acetyl-CoA:L-serine O-acetyltransferase

EC Number:

L-serine + acetyl-CoA <=> O-acetyl-L-serine + coenzyme A

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.

This reaction is reversible.

In Pathways: superpathway of sulfate assimilation and cysteine biosynthesis , L-cysteine biosynthesis I

Alternative Km values for this reaction include 0.56 mM for serine, and 0.11 mM for acetyl-CoA [Kredich66].

This reaction is reversible [Hindson03].

Inhibitors (Competitive): L-cysteine [Kredich66] , glycine [Hindson03]

Inhibitors (Unknown Mechanism): L-serine [Kredich66] , L-alanine [Hindson03]

Primary Physiological Regulators of Enzyme Activity: L-cysteine

Kinetic Parameters:

Km (μM)
kcat (sec-1)
kcat/Km (sec-1 μM-1)
[Kredich66, BRENDA14]
[Kredich66, BRENDA14]
[Hindson03, BRENDA14]
coenzyme A

pH(opt): 7.6 [BRENDA14, Kredich66], 7.6-7.8 [Kredich66]

Subunit of: cysteine synthase complex

Subunit composition of cysteine synthase complex = [(CysE)6][(CysK)2]
         serine acetyltransferase = (CysE)6 (extended summary available)
                 serine acetyltransferase monomer = CysE
         O-acetylserine sulfhydrylase A = (CysK)2 (extended summary available)
                 O-acetylserine sulfhydrylase A = CysK

Serine O-acetyl transferase is associated in a bifunctional complex with O-acetyl serine (thiol) lyase A (O-acetylserine sulfhydrylase A) [Denk87, Wigley90]. The complex dissociates in the presence of O-acetylserine, the product of the serine-O-acetyltransferase-catalyzed reaction [Neidhardt96, Wigley90, Denk87].

Citations: [Mino01, FeldmanSalit09]

Last-Curated ? 22-Mar-2007 by Shearer A , SRI International

Sequence Features

Protein sequence of serine acetyltransferase monomer with features indicated

Feature Class Location Citations Comment
Active-Site 143, 158
The active-site residues Asp-143 and His-158 form a catalytic triad with the substrate.

Gene Local Context (not to scale): ?

Gene local context diagram

Transcription Unit:

Transcription-unit diagram


10/20/97 Gene b3607 from Blattner lab Genbank (v. M52) entry merged into EcoCyc gene EG10187; confirmed by SwissProt match.


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."

Denk87: Denk D, Bock A (1987). "L-cysteine biosynthesis in Escherichia coli: nucleotide sequence and expression of the serine acetyltransferase (cysE) gene from the wild-type and a cysteine-excreting mutant." J Gen Microbiol 1987;133 ( Pt 3);515-25. PMID: 3309158

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

Feist07: Feist AM, Henry CS, Reed JL, Krummenacker M, Joyce AR, Karp PD, Broadbelt LJ, Hatzimanikatis V, Palsson BO (2007). "A genome-scale metabolic reconstruction for Escherichia coli K-12 MG1655 that accounts for 1260 ORFs and thermodynamic information." Mol Syst Biol 3;121. PMID: 17593909

FeldmanSalit09: Feldman-Salit A, Wirtz M, Hell R, Wade RC (2009). "A mechanistic model of the cysteine synthase complex." J Mol Biol 386(1);37-59. PMID: 18801369

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

GOA01a: GOA, DDB, FB, MGI, ZFIN (2001). "Gene Ontology annotation through association of InterPro records with GO terms."

Hindson00: Hindson VJ, Moody PC, Rowe AJ, Shaw WV (2000). "Serine acetyltransferase from Escherichia coli is a dimer of trimers." J Biol Chem 2000;275(1);461-6. PMID: 10617639

Hindson03: Hindson VJ, Shaw WV (2003). "Random-order ternary complex reaction mechanism of serine acetyltransferase from Escherichia coli." Biochemistry 42(10);3113-9. PMID: 12627979

Hindson03a: Hindson VJ (2003). "Serine acetyltransferase of Escherichia coli: substrate specificity and feedback control by cysteine." Biochem J 375(Pt 3);745-52. PMID: 12940772

Ishihama08: Ishihama Y, Schmidt T, Rappsilber J, Mann M, Hartl FU, Kerner MJ, Frishman D (2008). "Protein abundance profiling of the Escherichia coli cytosol." BMC Genomics 9;102. PMID: 18304323

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

Kredich66: Kredich NM, Tomkins GM (1966). "The enzymic synthesis of L-cysteine in Escherichia coli and Salmonella typhimurium." J Biol Chem 1966;241(21);4955-65. PMID: 5332668

Mino00: Mino K, Hiraoka K, Imamura K, Sakiyama T, Eisaki N, Matsuyama A, Nakanishi K (2000). "Characteristics of serine acetyltransferase from Escherichia coli deleting different lengths of amino acid residues from the C-terminus." Biosci Biotechnol Biochem 64(9);1874-80. PMID: 11055390

Mino00a: Mino K, Yamanoue T, Sakiyama T, Eisaki N, Matsuyama A, Nakanishi K (2000). "Effects of bienzyme complex formation of cysteine synthetase from escherichia coli on some properties and kinetics." Biosci Biotechnol Biochem 64(8);1628-40. PMID: 10993149

Mino01: Mino K, Imamura K, Sakiyama T, Eisaki N, Matsuyama A, Nakanishi K (2001). "Increase in the stability of serine acetyltransferase from Escherichia coli against cold inactivation and proteolysis by forming a bienzyme complex." Biosci Biotechnol Biochem 65(4);865-74. PMID: 11388466

Mino99: Mino K, Yamanoue T, Sakiyama T, Eisaki N, Matsuyama A, Nakanishi K (1999). "Purification and characterization of serine acetyltransferase from Escherichia coli partially truncated at the C-terminal region." Biosci Biotechnol Biochem 63(1);168-79. PMID: 10052138

Nakamori98: Nakamori S, Kobayashi SI, Kobayashi C, Takagi H (1998). "Overproduction of L-cysteine and L-cystine by Escherichia coli strains with a genetically altered serine acetyltransferase." Appl Environ Microbiol 64(5);1607-11. PMID: 9572924

Neidhardt96: Neidhardt FC, Curtiss III R, Ingraham JL, Lin ECC, Low Jr KB, Magasanik B, Reznikoff WS, Riley M, Schaechter M, Umbarger HE "Escherichia coli and Salmonella, Cellular and Molecular Biology, Second Edition." American Society for Microbiology, Washington, D.C., 1996.

Patrick07: Patrick WM, Quandt EM, Swartzlander DB, Matsumura I (2007). "Multicopy suppression underpins metabolic evolvability." Mol Biol Evol 24(12);2716-22. PMID: 17884825

Pye04: Pye VE, Tingey AP, Robson RL, Moody PC (2004). "The structure and mechanism of serine acetyltransferase from Escherichia coli." J Biol Chem 279(39);40729-36. PMID: 15231846

Sirko88: Sirko AE, Hulanicka DM (1988). "Cloning of cysE gene of Escherichia coli with a mini-Mu-lac containing a plasmid replicon." Acta Biochim Pol 35(1);51-5. PMID: 3140549

Sturgill04: Sturgill G, Toutain CM, Komperda J, O'Toole GA, Rather PN (2004). "Role of CysE in production of an extracellular signaling molecule in Providencia stuartii and Escherichia coli: loss of CysE enhances biofilm formation in Escherichia coli." J Bacteriol 186(22);7610-7. PMID: 15516574

Takagi99: Takagi H, Kobayashi C, Kobayashi S, Nakamori S (1999). "PCR random mutagenesis into Escherichia coli serine acetyltransferase: isolation of the mutant enzymes that cause overproduction of L-cysteine and L-cystine due to the desensitization to feedback inhibition." FEBS Lett 452(3);323-7. PMID: 10386615

Tei90: Tei H, Murata K, Kimura A (1990). "Structure and expression of cysX, the second gene in the Escherichia coli K-12 cysE locus." Biochem Biophys Res Commun 167(3);948-55. PMID: 2108679

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

UniProtGOA11a: 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."

Wigley90: Wigley DB, Derrick JP, Shaw WV (1990). "The serine acetyltransferase from Escherichia coli. Over-expression, purification and preliminary crystallographic analysis." FEBS Lett 1990;277(1-2);267-71. PMID: 2125278

Other References Related to Gene Regulation

Salvail10: Salvail H, Lanthier-Bourbonnais P, Sobota JM, Caza M, Benjamin JA, Mendieta ME, Lepine F, Dozois CM, Imlay J, Masse E (2010). "A small RNA promotes siderophore production through transcriptional and metabolic remodeling." Proc Natl Acad Sci U S A 107(34);15223-8. PMID: 20696910

Yamamoto15: Yamamoto K, Nakano M, Ishihama A (2015). "Regulatory role of transcription factor SutR (YdcN) in sulfur utilization in Escherichia coli." Microbiology 161(Pt 1);99-111. PMID: 25406449

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Please cite the following article in publications resulting from the use of EcoCyc: Nucleic Acids Research 41:D605-12 2013
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