Disease relevance of pssA

• Sequence and inactivation of the pss gene of Escherichia coli. Phosphatidylethanolamine may not be essential for cell viability [1].
• The products of Rhizobium genes, psi and pss, which affect exopolysaccharide production, are associated with the bacterial cell surface [2].
• H. pylori PSS exhibits significant amino acid sequence identity with the PSS proteins found in the archaebacterium Methanococcus jannaschii, the gram-positive bacterium Bacillus subtilis, and the yeast Saccharomyces cerevisiae but none with its Escherichia coli counterpart [3].
• The Helicobacter pylori gene encoding phosphatidylserine synthase: sequence, expression, and insertional mutagenesis [3].
• The lesions in two of the solvent-sensitive mutants (DC7 and DC9) and one of the resistant mutants (DC11) were mapped by cotransduction with phage P1 and shown to lie very close to the pss locus at 56 min on the Escherichia coli map [4].

High impact information on pssA

• The witA gene located between pss and rrnG on the Escherichia coli chromosome encodes a 432-amino acid protein [5].
• We have screened a bank of 2000 E. coli strains carrying hybrid ColE1 plasmids [Clarke, L. & Carbon, J. (1976) Cell 9, 91-99] for those that correct the temperature sensitivity of a mutant in CDP-1,2-diacyl sn-glycerol:L-serine O-phosphatidyltransferase (EC 2.7.8.8, phosphatidylserine synthase) [6].
• Membranes from an E. coli pss knockout mutant grown on 50 mm CaCl(2), which lack phosphatidylethanolamine, do not contain measurable transferase activity unless exogenous phosphatidylethanolamine is added back to the assay system [7].
• We now report the purification of this lipid from a pss(-) pmrA(C) mutant of E. coli and assign its structure as undecaprenyl phosphate-alpha-l-Ara4N [8].
• Phosphatidylserine synthase can be dissociated from ribosomes in the presence of various inorganic salts at high ionic strength [9].

Chemical compound and disease context of pssA

• Phosphatidylserine synthase from Escherichia coli. The role of Triton X-100 in catalysis [10].
• We point out the possibilities of minor cardiolipin formation by phosphatidylserine synthase and of the essential nature of cardiolipin for the survival of E. coli cells [11].
• A manganese-dependent PSS activity was found in the membrane fractions of the E. coli cells overexpressing the H. pylori pss gene product [3].

Biological context of pssA

• This gene, designated pssA, is localized on the large plasmid that also harbours the STEC haemolysin operon [12].
• In the pssA mutant, II(Glc) and II(Man) activities were depressed both in vivo and in vitro, with the in vivo transport activities being depressed much more than the in vitro phosphorylation activities [13].
• It was concluded that M. thermautotrophicus archaetidylserine synthase belongs to subclass II phosphatidylserine synthase (B. subtilis type) on the basis of not only homology but also substrate specificity and some enzymatic properties [14].
• In this report we show that wild-type pss and psd genes are required for motility and chemotaxis [15].
• A gene (MT1027) in M. thermautotrophicus genome annotated as the gene encoding phosphatidylserine synthase was found to be homologous to Bacillus subtilis pssA but not to Escherichia coli pssA [14].

Anatomical context of pssA

• II(Man) and II(Glc) exhibited greater thermal lability in the pssA mutant membranes than in the wild-type membranes, but II(Mtl) showed enhanced thermal stability [13].

Associations of pssA with chemical compounds

• Elevation of the level of micF RNA was not restricted to acidic-phospholipid deficiency: OmpF was hardly detected and micF RNA was present 2.7 to 2.8 times more in a pssA null mutant that lacked phosphatidylethanolamine [16].
• Green fluorescent protein fusions to the enzymes that catalyze the committed steps in PE synthesis, phosphatidylserine synthase, and in CL synthesis, CL synthase and phosphatidylglycerophosphate synthase, were localized mainly in the septal membranes in B. subtilis cells [17].
• Instead, phosphatidylserine synthase (cytidine 5'-diphosphate-diglyceride:L-serine phosphatidyl transferase) and phosphatidylserine decarboxylase were detected, although at low levels [18].
• Interactions with PlsB, a sn-glycerol-3-phosphate acyltransferase and PssA, a phosphatidylserine synthase, were identified and validated, showing that YbgC is involved in phospholipid metabolism [19].
• These results, together with previous observations, indicate that phosphatidylserine synthesis requires the membrane-associated form of phosphatidylserine synthase, which is related to the membrane-levels of acidic phospholipids, thus yielding balanced compositions of zwitterionic and acidic phospholipids [20].

Analytical, diagnostic and therapeutic context of pssA

• Amino acid residue 56 of the phosphatidylserine synthase of Bacillus subtilis was changed from Ser to Pro by using modified primers in PCR amplification of its structural gene, pssBS [21].

References