FIG. 2.

Construction of plasmid pAMCshA. The cshA gene and flanking regions were PCR amplified from S. gordonii DL1 DNA, and the SmaI-XbaI segment (8.1 kb) was ligated into the E. coli-E. faecalis shuttle vector pAM401 digested with EcoRV and XbaI as detailed in Materials and Methods. The structural features of the CshA polypeptide are shown as follows: L, leader peptide (41 amino acid residues); NR, nonrepetitive region (residues 42 to 878); R, amino acid repeat block region (residues 879 to 2417); A, cell wall anchor (residues 2418 to 2508); aa, amino acids; P, promoter; Ω, rho-independent transcriptional terminator.