Primary structure and function of a cytotoxic outer-membrane protein (ComP) of Plesiomonas shigelloides.
We previously isolated and characterized a 40-kDa cytotoxic outer-membrane protein (ComP) produced by Plesiomonas shigelloides strain P-1 (P-1). Sequence analysis of the comP gene revealed a coding region of 1068 bp, with a predicted mature protein composed of 335 amino acids and a molecular mass of 38.597 kDa. Three-dimensional structural modeling of ComP suggests that it has a beta-barrel structure with 16 transmembrane strands, eight short periplasmic turns and eight external loops. blast search results and protein modeling suggest that ComP may be a novel porin protein of P. shigelloides. In order to understand the role of ComP during P. shigelloides infection, we constructed a deletion mutant strain (P. shigelloides DeltacomP; P-1201), and compared the pathogenicity of P-1201 vs. the wild-type strain P-1 in Caco-2 cells. Unlike P-1, the deletion strain P-1201 was not cytotoxic to Caco-2 cells and did not lead to apoptosis. These data indicate that ComP may be the predominant virulence factor that triggers cell death in the host cells following infection.
Tsugawa
Hitoshi
H
Department of Infection and Host Defense, Tohoku Pharmaceutical University, Sendai Aoba-ku, Miyagi, Japan.
Ogawa
Asako
A
Takehara
Satomi
S
Kimura
Mayumi
M
Okawa
Yoshio
Y
D000595:Amino Acid Sequence; D017209:Apoptosis; D001425:Bacterial Outer Membrane Proteins / Q000737:chemistry* / Q000235:genetics; D018938:Caco-2 Cells; D003603:Cytotoxins / Q000737:chemistry* / Q000235:genetics; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D017353:Gene Deletion; D006801:Humans; D008958:Models, Molecular; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009499:Neutral Red / Q000378:metabolism; D016366:Open Reading Frames; D016981:Plesiomonas / Q000737:chemistry* / Q000235:genetics / Q000472:pathogenicity; D018272:Porins / Q000737:chemistry / Q000235:genetics; D017434:Protein Structure, Tertiary; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D037521:Virulence Factors / Q000737:chemistry / Q000235:genetics
D001425:Bacterial Outer Membrane Proteins; D003603:Cytotoxins; D004269:DNA, Bacterial; D018272:Porins; D037521:Virulence Factors; D009499:Neutral Red