Differentially conserved staphylococcal SH3b_5 cell wall binding domains confer increased staphylolytic and streptolytic activity to a streptococcal prophage endolysin domain.

Authors: Donovan, David; Foster Frey, Juli; STODOLA, ANGELINE - Third Wave Technologies; ANNACKER, DANIEL - Johns Hopkins University; Becker, Stephen

Submitted to: Gene
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/24/2009
Publication Date: 5/5/2009
Citation: Becker, S.C., Foster-Frey, J., Stodola, A.J., Anacker, D., Donovan, D.M., 2009. Differentially conserved staphylococcal SH3b_5 cell wall binding domains confer identical staphylolytic activity to a streptococcal prophage endolysin lytic domain. FEMS Immunology and Medical Microbiology. 443(1-2):32-41.

Interpretive Summary: Staphylococcal peptidoglycan hydrolases are a potent new source of antimicrobials. A large subset of these proteins contain a C-terminal SH3b_5 cell wall binding domain that has been shown for some to be essential for accurate cell wall recognition and subsequent staphylolytic activity. Fifty proteins of staphylococcal origin, with these C-terminal sequences have been aligned and homologues identified. C-terminal domain alignment assigns a staphylococcal binding region consensus with two distinct groups of proteins with over-lapping but differentially conserved residues. Three new putative intron containing phage endolysin genes have also been identified for the phages G1, X2 and 85.

Technical Abstract: Staphylococcal peptidoglycan hydrolases are a potential new source of antimicrobials. A large subset of these proteins contain a C-terminal SH3b_5 cell wall binding domain that has been shown for some to be essential for accurate cell wall recognition and subsequent staphylolytic activity, properties that could enhance the antimicrobial quality of the protein. Fifty proteins of staphylococcal origin, harboring these C-terminal sequences have been aligned and homologues identified. Five highly repetitive groups of proteins with >90% identity have been defined. Representative C-termini from each of these five groups and another six staphylococcal proteins, for which no highly conserved homologues have been identified, are aligned and sequence conservation presented. A hypothesis and premise behind this work was that there might be specie-specific conservation of cell wall binding regions that could be used to target a variety of antimicrobials in a specie specific manner. C-terminal domain alignment does indicate two distinct groups of proteins with over-lapping but differentially conserved residues. Unexpectedly, a higher degree of conservation is observed in the group comprising proteins from a variety of staphylococcal species (or their phage), rather than the group reported from S. aureus alone. Through this exercise, three new putative intron containing phage endolysin genes have also been identified for the phages G1, X2 and 85.