Escherichia coli K-12 substr. MG1655 Enzyme: phosphatidylserine synthase

Gene: pssA Accession Numbers: EG10781 (EcoCyc), b2585, ECK2583

Synonyms: pss

Regulation Summary Diagram: ?

Regulation summary diagram for pssA

Subunit composition of phosphatidylserine synthase = [PssA]

Phosphatidylserine synthase catalyzes the de novo synthesis of phosphatidylserine from which phosphatidylethanolamine is subsequently synthesized. This represents the first committed step to phosphatidylethanolamine biosynthesis from precursors. The enzyme is unique among the phospholipid biosynthetic enzymes in that it is not membrane associated but tightly bound to ribosomes. The reaction consists of a two-step Ping-Pong mechanism. [Dowhan92a, Raetz78, Raetz74]

The pssA gene from E. coli has been cloned and expressed in B. subtilis and recombinant PssA characterised [Zhang09c].

Locations: cytosol, inner membrane

Map Position: [2,720,749 -> 2,722,104] (58.64 centisomes, 211°)
Length: 1356 bp / 451 aa

Molecular Weight of Polypeptide: 52.802 kD (from nucleotide sequence)

pI: 8.73

Unification Links: ASAP:ABE-0008510 , CGSC:355 , DIP:DIP-10593N , EchoBASE:EB0774 , EcoGene:EG10781 , EcoliWiki:b2585 , Mint:MINT-1218158 , ModBase:P23830 , OU-Microarray:b2585 , PortEco:pssA , PR:PRO_000023620 , Pride:P23830 , Protein Model Portal:P23830 , RefSeq:NP_417080 , RegulonDB:EG10781 , SMR:P23830 , String:511145.b2585 , UniProt:P23830

Relationship Links: InterPro:IN-FAMILY:IPR001736 , InterPro:IN-FAMILY:IPR016270 , Panther:IN-FAMILY:PTHR12586 , Pfam:IN-FAMILY:PF00614 , Prosite:IN-FAMILY:PS50035 , Smart:IN-FAMILY:SM00155

In Paralogous Gene Group: 437 (2 members)

Gene-Reaction Schematic: ?

Gene-Reaction Schematic

GO Terms:

Biological Process: GO:0006629 - lipid metabolic process Inferred by computational analysis [UniProtGOA11]
GO:0008654 - phospholipid biosynthetic process Inferred by computational analysis [UniProtGOA11, GOA01]
Molecular Function: GO:0003882 - CDP-diacylglycerol-serine O-phosphatidyltransferase activity Inferred from experiment Inferred by computational analysis [GOA01a, Zhang09c]
GO:0003824 - catalytic activity Inferred by computational analysis [GOA01]
GO:0016740 - transferase activity Inferred by computational analysis [UniProtGOA11]
GO:0016780 - phosphotransferase activity, for other substituted phosphate groups Inferred by computational analysis [GOA01]
Cellular Component: GO:0005829 - cytosol Inferred from experiment Inferred by computational analysis [DiazMejia09, Ishihama08]
GO:0005737 - cytoplasm Inferred by computational analysis [UniProtGOA11a, UniProtGOA11]
GO:0005886 - plasma membrane Inferred by computational analysis [UniProtGOA11a, UniProtGOA11]
GO:0016020 - membrane Inferred by computational analysis [UniProtGOA11]

MultiFun Terms: cell structure membrane
metabolism biosynthesis of macromolecules (cellular constituents) phospholipid

Essentiality data for pssA knockouts: ?

Growth Medium Growth? T (°C) O2 pH Osm/L Growth Observations
LB Lennox No 37 Aerobic 7   No [Baba06, Comment 1]

Enzymatic reaction of: phosphatidylserine synthase

Synonyms: CDPdiacylglycerol-serine O-phosphatidyltransferase, CDPdiglyceride-serine O-phosphatidyltransferase, CDPdiacylglycerol:L-serine 3-O-phosphatidyltransferase

EC Number:

a CDP-diacylglycerol + L-serine <=> CMP + an L-1-phosphatidylserine + H+

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

This reaction is reversible.

Alternative Substrates for CMP [Comment 2 ]: dCMP [Raetz74 ]

In Pathways: superpathway of phospholipid biosynthesis I (bacteria) , phosphatidylethanolamine biosynthesis I

Kinetic Parameters:

Km (μM)
[Ishinaga74, BRENDA14]

T(opt): 35 °C [BRENDA14, Zhang09c]

pH(opt): 7 [BRENDA14, Zhang09c], 8 [BRENDA14, Zhang09c]

Sequence Features

Protein sequence of PssA with features indicated

Feature Class Location Citations Comment
Protein-Segment 4 -> 9
UniProt: Lys-rich (basic); Sequence Annotation Type: compositionally biased region;
Sequence-Conflict 32
[DeChavigny91, UniProt10]
UniProt: (in Ref. 1; AAA97504);
Sequence-Conflict 78
[DeChavigny91, UniProt10]
UniProt: (in Ref. 1; AAA97504);
Protein-Segment 119 -> 154
UniProt: Hydrophobic; Sequence Annotation Type: region of interest;
Conserved-Region 133 -> 159
UniProt: PLD phosphodiesterase 1;
Sequence-Conflict 165 -> 167
[DeChavigny91, UniProt10]
UniProt: (in Ref. 1; AAA97504);
Protein-Segment 239 -> 284
UniProt: Hydrophobic; Sequence Annotation Type: region of interest;
Sequence-Conflict 287 -> 288
[DeChavigny91, UniProt10]
UniProt: (in Ref. 1; AAA97504);
Sequence-Conflict 309
[DeChavigny91, UniProt10]
UniProt: (in Ref. 1; AAA97504);
Conserved-Region 352 -> 379
UniProt: PLD phosphodiesterase 2;
Protein-Segment 430 -> 449
UniProt: Arg/Lys-rich (basic); Sequence Annotation Type: compositionally biased region;

Gene Local Context (not to scale): ?

Gene local context diagram

Transcription Unit:

Transcription-unit diagram


Peter D. Karp on Wed Jan 18, 2006:
Gene left-end position adjusted based on analysis performed in the 2005 E. coli annotation update [Riley06 ].
10/20/97 Gene b2585 from Blattner lab Genbank (v. M52) entry merged into EcoCyc gene EG10781; 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."

DeChavigny91: DeChavigny A, Heacock PN, Dowhan W (1991). "Sequence and inactivation of the pss gene of Escherichia coli. Phosphatidylethanolamine may not be essential for cell viability." J Biol Chem 266(8);5323-32. PMID: 2002065

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

Dowhan92a: Dowhan W (1992). "Phosphatidylserine synthase from Escherichia coli." Methods Enzymol 1992;209;287-98. PMID: 1323044

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.

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

Ishinaga74: Ishinaga M, Kato M, Kito M (1974). "Effects of phospholipids on soluble phosphatidylserine synthetase of Escherichia coli." FEBS Lett 49(2);201-2. PMID: 4613576

Raetz74: Raetz CR, Kennedy EP (1974). "Partial purification and properties of phosphatidylserine synthetase from Escherichia coli." J Biol Chem 1974;249(16);5083-45. PMID: 4604873

Raetz78: Raetz CR (1978). "Enzymology, genetics, and regulation of membrane phospholipid synthesis in Escherichia coli." Microbiol Rev 1978;42(3);614-59. PMID: 362151

Riley06: Riley M, Abe T, Arnaud MB, Berlyn MK, Blattner FR, Chaudhuri RR, Glasner JD, Horiuchi T, Keseler IM, Kosuge T, Mori H, Perna NT, Plunkett G, Rudd KE, Serres MH, Thomas GH, Thomson NR, Wishart D, Wanner BL (2006). "Escherichia coli K-12: a cooperatively developed annotation snapshot--2005." Nucleic Acids Res 34(1);1-9. PMID: 16397293

UniProt09: UniProt Consortium (2009). "UniProt version 15.8 released on 2009-10-01 00:00:00." Database.

UniProt10: UniProt Consortium (2010). "UniProt version 2010-11 released on 2010-11-02 00:00:00." Database.

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."

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

Zhang09c: Zhang YN, Lu FP, Chen GQ, Li Y, Wang JL (2009). "Expression, purification, and characterization of phosphatidylserine synthase from Escherichia coli K12 in Bacillus subtilis." J Agric Food Chem 57(1);122-6. PMID: 19072541

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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, biocyc13.