Lemaire Marc, Miras Isabelle, Gounon Pierre, Béguin Pierre
Unité de Physiologie Cellulaire and URA 1300 CNRS, Département des Biotechnologies, Institut Pasteur, 28 rue du Dr Roux, 75724 Paris Cedex 15, France.
Station de Microscopie Electronique, Institut Pasteur, 28 rue du Dr Roux, 75724 Paris Cedex 15, France.
Microbiology (Reading). 1998 Jan;144 ( Pt 1):211-217. doi: 10.1099/00221287-144-1-211.
The protomer forming the S-layer of Clostridium thermocellum was identified as a 140 kDa protein which was non-covalently bound to the cell wall. Cloning and sequencing of the corresponding gene revealed an open reading frame of 3108 nucleotides encoding a polypeptide of 1036 amino acids, termed SlpA. The amino acid composition of SlpA matches the composition of a previously described exocellular glycoprotein. SlpA shared extensive similarity with the S-layer protein of Bacillus sphaericus and with the outer wall protein of Bacillus brevis. In addition, the amino-terminal region of SlpA contained a segment presenting similarities with segments termed SLH (S-layer homologous), which are found in several bacterial exoproteins. A polypeptide of 209 residues comprising this segment was shown to bind to cell walls extracted from C. thermocellum cells.
形成嗜热栖热放线菌S层的原体被鉴定为一种140 kDa的蛋白质，它与细胞壁非共价结合。相应基因的克隆和测序揭示了一个3108个核苷酸的开放阅读框，编码一个1036个氨基酸的多肽，称为SlpA。SlpA的氨基酸组成与先前描述的胞外糖蛋白的组成相匹配。SlpA与球形芽孢杆菌的S层蛋白和短短芽孢杆菌的外壁蛋白有广泛的相似性。此外，SlpA的氨基末端区域包含一个与称为SLH（S层同源）的片段相似的片段，该片段存在于几种细菌外蛋白中。包含该片段的209个残基的多肽被证明能与从嗜热栖热放线菌细胞中提取的细胞壁结合。
