This family represents T4 phage gp25 protein and gp25-like proteins, found in several systems, including contractile tail bacteriophages, the type VI secretion system (T6SS) and R-type pyocins, which constitute a multiprotein tubular apparatus to attach to and penetrate host cell membranes. Gp25 is a component of the conserved wedge in the inner part of the baseplate and serves as a nucleus for sheath polymerisation, playing a critical role in sheath assembly and contraction [1,2]. The EPR motif (Glu-Pro-Arg, residues 85-87 of gp25) is conserved across all members of the family including orthologues from the RpoS-mediated general stress response system (called IraD) [3,4]. This motif interacts with the 'core bundle' composed of orthologues of T4 gp6 and gp7 proteins in contractile injection systems. [1]. 27193680. Structure of the T4 baseplate and its function in triggering sheath contraction. Taylor NM, Prokhorov NS, Guerrero-Ferreira RC, Shneider MM, Browning C, Goldie KN, Stahlberg H, Leiman PG;. Nature. 2016;533:346-352. [2]. 21873404. Structure-function analysis of HsiF, a gp25-like component of the type VI secretion system, in Pseudomonas aeruginosa. Lossi NS, Dajani R, Freemont P, Filloux A;. Microbiology. 2011;157:3292-3305. [3]. 21639793. The RpoS-mediated general stress response in Escherichia coli. Battesti A, Majdalani N, Gottesman S;. Annu Rev Microbiol. 2011;65:189-213. [4]. 30975721. Structural basis for inhibition of a response regulator of sigma(S) stability by a ClpXP antiadaptor. Dorich V, Brugger C, Tripathi A, Hoskins JR, Tong S, Suhanovsky MM, Sastry A, Wickner S, Gottesman S, Deaconescu AM;. Genes D. TRUNCATED at 1650 bytes (from Pfam)
- Date:
- 2024-10-16