Identification of Two Binding Domains, One for Peptidoglycan and Another for a Secondary Cell Wall Polymer, on the N-Terminal Part of the S-Layer Protein SbsB from Bacillus stearothermophilus PV72/p2

First studies on the structure-function relationship of the S-layer protein from B. stearothermophilus PV72/p2 revealed the coexistence of two binding domains on its N-terminal part, one for peptidoglycan and another for a secondary cell wall polymer (SCWP). The peptidoglycan binding domain is located between amino acids 1 to 138 of the mature S-layer protein comprising a typical S-layer homologous domain. The SCWP binding domain lies between amino acids 240 to 331 and possesses a high serine plus glycine content.