The N-terminal region of the Oenococcus oeni bacteriophage fOg44 lysin behaves as a bona fide signal peptide in Escherichia coli and as a cis-inhibitory element, preventing lytic activity on oenococcal cells

Citation
C. Sao-jose et al., The N-terminal region of the Oenococcus oeni bacteriophage fOg44 lysin behaves as a bona fide signal peptide in Escherichia coli and as a cis-inhibitory element, preventing lytic activity on oenococcal cells, J BACT, 182(20), 2000, pp. 5823-5831
Citations number
42
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Microbiology
Journal title
JOURNAL OF BACTERIOLOGY
ISSN journal
0021-9193 → ACNP
Volume
182
Issue
20
Year of publication
2000
Pages
5823 - 5831
Database
ISI
SICI code
0021-9193(200010)182:20<5823:TNROTO>2.0.ZU;2-U
Abstract
The function of the N-terminal region of the Oenococcus oeni phage fOg44 ly sin (Lys44) as an export signal was investigated. We observed that when ind uced in Escherichia coli, Lys44 was cleaved between residues 27 and 28 in a SecA-dependent manner. Lys34 processing could be blocked by a specific sig nal peptidase inhibitor and was severely reduced by modification of the cle avage site. The lethal effect of Lys44 expression observed in E, coli was a scribed to the presence of its N-terminal 27-residue sequence, as its delet ion resulted in the production of a nontoxic, albeit active, product. We ha ve further established that lytic activity in oenococcal cells was dependen t on Lys44 processing, An active protein with the molecular mass expected f or the cleaved enzyme was detected in extracts from O, oeni-infected cells. The temporal pattern of its appearance suggests that synthesis and export of Lys44 in the infected host progress along with phage maturation. Overall , these results provide, for the first time, experimental evidence for the presence of a signal peptide in a bacteriophage lysin, Database searches an d alignment of protein sequences support the prediction that other known O, oeni and Lactococcus lactis phages also encode secretory lysins, The evolu tionary significance of a putative phage lysis mechanism relying on secreto ry lytic enzymes is tentatively discussed, on the basis of host cell wall s tructure and autolytic capacity.