The DNA sequence encoding pldA gene, the structural gene for detergent-resistant phospholipase A of E. coli.
The nucleotide sequence of the pldA gene of Escherichia coli K-12, which codes for detergent-resistant phospholipase A (DR-phospholipase A), located in the outer membrane, was determined and the amino acid sequence of DR-phospholipase A was deduced. DR-phospholipase A contains 269 amino acids, resulting in a protein with a molecular weight of 30,809. It does not contain any cysteine residues and seems to be synthesized first as a precursor with a typical signal peptide composed of 20 amino acids. The NH2-terminus of the mature protein is glutamine, a polar amino acid, while other outer membrane proteins so far determined have a nonpolar amino acid there. The hydropathy profile of the deduced amino acid sequence of DR-phospholipase A was studied. Most of the region was rather hydrophilic and there were no stretches of hydrophobic amino acids. Computer analysis showed that there are no homologies between DR-phospholipase A and other extracellular phospholipases whose amino acid sequences are known. The candidates for the promoter region of the pldA gene, the 5'-flanking region, have a significantly high AT content, while the AT content of the coding region is about the same as the average AT content of the E. coli chromosome. A typical rho-independent transcription termination site is also present at the 3'-flanking region. This is the first example of the primary structure of a membrane-bound phospholipase.
D000595:Amino Acid Sequence; D001483:Base Sequence; D003062:Codon; D004269:DNA, Bacterial / Q000302:isolation & purification*; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics; D005796:Genes; D005798:Genes, Bacterial; D010455:Peptides / Q000032:analysis / Q000235:genetics; D010740:Phospholipases / Q000096:biosynthesis*; D010741:Phospholipases A / Q000032:analysis / Q000096:biosynthesis*; D010957:Plasmids; D021382:Protein Sorting Signals
D003062:Codon; D004269:DNA, Bacterial; D010455:Peptides; D021382:Protein Sorting Signals; D010740:Phospholipases; D010741:Phospholipases A