RT Journal Article SR Electronic(1) A1 Rogers, Jeffrey D. A1 Haase, Elaine M. A1 Brown, Alan E. A1 Douglas, Charles W. I A1 Gwynn, Justin P. A1 Scannapieco, Frank A.YR 1998 T1 Identification and analysis of a gene (abpA) encoding a major amylase-binding protein in Streptococcus gordonii JF Microbiology, VO 144 IS 5 SP 1223 OP 1233 DO https://doi.org/10.1099/00221287-144-5-1223 PB Microbiology Society, SN 1465-2080, AB Oral streptococci such as Streptococcus gordonii bind the abundant salivary enzyme x-amylase. This interaction may be important in dental plaque formation and metabolism, thus contributing to the initiation and progression of dental caries and periodontal disease, the two most common plaque-mediated diseases. The conjugative transposon Tn916 was used to insertionally inactivate gene(s) essential to the expression of amylase-binding components of S. gordonii Challis, and a mutant deficient in amylase-binding (Challis Tn1) was identified. While wild-type strains of S. gordonii released both 20 kDa and 82 kDa amylase-binding proteins into culture supernatants, Challis Tn1 expressed the 82 kDa but not the 20 kDa protein. The 20 kDa amylase-binding protein was isolated from culture supernatants of S. gordonii Challis by hydroxyapatite chromatography. A partially purified, functionally active 20 kDa protein was sequenced from blots, and the N-terminal sequence obtained was found to be DEP (A) TDAAT(R)NND. A novel strategy, based on the single-specific-primer polymerase chain reaction technique, enabled the gene inactivated by Tn916 to be cloned. Analysis of the resultant nucleotide sequence revealed an open reading frame of 585 bp, designated amylase-binding protein A (abpA), encoding a protein of 20 kDa (AbpA), immediately downstream from the insertion site of Tn916. This protein possessed a potential signal peptide followed by a region having identity with the N-terminal sequence of the 20 kDa amylase-binding protein. These results demonstrate the role of the 20 kDa protein in the binding of amylase to S. gordonii. Knowledge of the nature of amylase-binding proteins may provide a better understanding of the role of these proteins in the colonization of S. gordonii in the oral cavity., UL https://www.microbiologyresearch.org/content/journal/micro/10.1099/00221287-144-5-1223