Protein Family Models

This family comprises lipoproteins from four gamma proteobacterial species: PulS protein of Klebsiella pneumoniae (P20440), the OutS protein of Erwinia chrysanthemi (Q01567) and Pectobacterium chrysanthemi, and the functionally uncharacterized E. coli protein EtpO. PulS and OutS have been shown to interact with and facilitate insertion of secretins into the outer membrane, suggesting a chaperone-like, or piloting function for members of this family [1,2]. In the pilotin from this four-helix protein from enterohemorrhagic Escherichia coli, the straight helix alpha2, the curved helix alpha3 and the bent helix alpha4 surround the central N-terminal helix alpha1. These helices create a prominent groove, mainly formed by side chains of helices 1,2 and 3 suggesting this groove is important as a binding site [3]. [1]. 2661532. Klebsiella pneumoniae pulS gene encodes an outer membrane lipoprotein required for pullulanase secretion. D'Enfert C, Pugsley AP;. J Bacteriol. 1989;171:3673-3679. [2]. 22466878. The type II secretion system: biogenesis, molecular architecture and mechanism. Korotkov KV, Sandkvist M, Hol WG;. Nat Rev Microbiol. 2012;10:336-351. [3]. 23458689. Crystal structure of the pilotin from the enterohemorrhagic Escherichia coli type II secretion system. Korotkov KV, Hol WG;. J Struct Biol. 2013;182:186-191. (from Pfam)

Date:

2024-10-16

Members of this, including YacC from Escherichia coli K-12, resemble the lipoprotein GspS of type II secretion systems (T2SS), but in general are not lipoproteins. In E. coli K-12, where the T2SS is cryptic (not expressed, but able to function after manipulation to force its express), YacC is encoded far from the locus where the main set of T2SS genes are found, and it is not clear that YacC is a true GspS.

Date:

2020-10-26