P35 holin family explained

The PRD1 Phage P35 Holin (P35 Holin) Family (TC# 1.E.5) is a member of Holin Superfamily III.^[1] The prototype for this family is the lipid-containing PRD1 enterobacterial phage holin protein P35 (12.8 kDa; TC# 1.E.5.1.1) encoded by gene XXXV (orfT).^[2] It is a component of a typical holin-endolysin system which functions to lyse the host bacterial cell.

Structure

P35 holin (TC# 1.E.5.1.1) has 3 transmembrane segments (TMSs) with 5 positively charged residues between TMSs 1 and 2. It has 4 positively charged residues at the C-terminus. It is therefore thought that the N-terminus is in the periplasm and the C-terminus is in the cytoplasm. Homologues of 109 amino acyl residues (aas), which also have 3 putative TMSs, are encoded in the genomes of Xylella fastidiosa strains.

Function

The reaction catalyzed by P35 holin is:

autolysin (in) → autolysin (out)

See also

• Bacteriophage
• Phage typing
• Holin
• Lysin
• Transporter Classification Database

Notes and References

1. Reddy. Bhaskara L.. Saier. Milton H.. 2013-11-01. Topological and phylogenetic analyses of bacterial holin families and superfamilies. Biochimica et Biophysica Acta (BBA) - Biomembranes. 1828. 11. 2654–2671. 10.1016/j.bbamem.2013.07.004. 0006-3002. 3788059. 23856191.
2. Rydman. Pia S.. Bamford. Dennis H.. 2003-07-01. Identification and mutational analysis of bacteriophage PRD1 holin protein P35. Journal of Bacteriology. 185. 13. 3795–3803. 0021-9193. 161566. 12813073. 10.1128/jb.185.13.3795-3803.2003.