A new cell surface proteinase: sequencing and analysis of the prtB gene from Lactobacillus delbruekii subsp. bulgaricus.
Investigation of the chromosomal region downstream of the lacZ gene from Lactobacillus delbrueckii subsp. bulgaricus revealed the presence of a gene (prtB) encoding a proteinase of 1,946 residues with a predicted molecular mass of 212 kDa. The deduced amino acid sequence showed that PrtB proteinase displays significant homology with the N termini and catalytic domains of lactococcal PrtP cell surface proteinases and is probably synthesized as a preproprotein. However, the presence of a cysteine near the histidine of the PrtB active site suggests that PrtB belongs to the subfamily of cysteine subtilisins. The C-terminal region strongly differs from those of PrtP proteinases by having a high lysine content, an imperfect duplication of 41 residues, and a degenerated sequence compared with the consensus sequence for proteins anchoring in the cell walls of gram-positive bacteria. Finally, the product of the truncated prtM-like gene located immediately upstream of the prtB gene seems too short to be involved in the maturation of PrtB.
Gilbert
C
C
Laboratoire de Microbiologie et Génétique Moléculaire, UMR CNRS 106,Université Claude Bernard-Lyon I, France.
Atlan
D
D
Blanc
B
B
Portailer
R
R
Germond
J E
JE
Lapierre
L
L
Mollet
B
B
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics*; D001483:Base Sequence; D001665:Binding Sites; D004269:DNA, Bacterial / Q000737:chemistry; D010450:Endopeptidases / Q000737:chemistry / Q000235:genetics*; D005798:Genes, Bacterial; D007778:Lactobacillus / Q000201:enzymology / Q000235:genetics*; D008565:Membrane Proteins / Q000235:genetics*; D008969:Molecular Sequence Data; D012697:Serine Endopeptidases
D001426:Bacterial Proteins; D004269:DNA, Bacterial; D008565:Membrane Proteins; D010450:Endopeptidases; D012697:Serine Endopeptidases; C085783:lactocepin; C099750:PrtB protein, bacteria