ompT: Escherichia coli K-12 Structural Gene for Protein a (3b)

Abstract

Chromosomal DNA from strain UT400, a previously described deletion mutant of Escherichia coli K-12 that lacks outer membrane protein a, failed to hybridize with plasmid DNA (pGGC110) containing the structural gene for protein a. We designate the genetic locus for protein a, located at approximately 12.5 min of the E. coli chromosome, ompT.

Peptidases and proteases of Escherichia coli and Salmonella typhimurium

“…Protease OmpT is a major outer membrane protein which is also known as protein a or 3b [23,92,101]. Biochemical and genetic studies indicate that the OmpT protein is a trypsin-like protease involved in processing the ferric enterobactin 271 receptor (Fep) protein from an active (81 kDa) into an inactive (74 kDa) form [25].…”

“…OmpT is identical to protease VII which is known to degrade human gamma interferon produced by recombinant E. coli [100]. The ompT gene was located at 12.5 min on the chromosome; it has been sequenced [42], and its expression can be modulated by envZ [92]. It is also likely that the colicin protease (Cpr) previously described [8] is protease VII.…”

Keratinocyte Growth Factor-2 Production in an ompT-Deficient Escherichia coli K-12 Mutant

“…These observations led to the postulation that the protease responsible for KGF‐2 degradation was OmpT (19–21). This 297‐amino‐acid protease is localized to the outer membrane and has been shown to degrade proteins between cationic residues and also between cationic residues and several apolar residues (19,35–40). Ironically, the cleavage of A63−S208 KGF‐2 by OmpT occurred between Arg and Ser residues that have not yet been described in the published literature as an OmpT‐targeted site.…”

“…Although the addition of guanidine‐HCl inhibited the protease activity, this scheme resulted in excessive product loss due to precipitation. In this work, we identified and deleted the gene encoding the culprit protease, OmpT (19–21), from the E. coli genome. Production of the A63−S208 KGF‐2 protein in this novel host nearly abolished the N‐terminal specific proteolytic degradation.…”

Prevalence of ompT among Escherichia coli isolates of human origin

“…A number of proteins may serve as substrates for OmpT [2][3][4][5][6][7]; however, the actual physiological function of OmpT remains elusive. The gene encoding the OmpT protease has been mapped, cloned and sequenced [1,8,9]. The ompT nucleotide sequence is similar to the plasminogen activator gene, pla, of Yersinia pestis [10].…”