SpyA is a membrane-bound ADP-ribosyltransferase of Streptococcus pyogenes which modifies a streptococcal peptide, SpyB. Mol Microbiol 2012 Mar;83(5):936-52
Date
02/01/2012Pubmed ID
22288436Pubmed Central ID
PMC3288127DOI
10.1111/j.1365-2958.2012.07979.xScopus ID
2-s2.0-84857356903 (requires institutional sign-in at Scopus site) 11 CitationsAbstract
All sequenced genomes of Streptococcus pyogenes (Group A Streptococcus, GAS) encode a protein, SpyA, with homology to C3-like ADP-ribosyltransferase toxins. SpyA is a novel virulence factor which plays a role in pathogenesis in a mouse model of soft-tissue infection. In this study we demonstrate that SpyA is a surface-exposed membrane protein which is anchored to the streptococcal membrane by an N-terminal transmembrane sequence. We identified a small gene upstream of spyA, designated spyB, which encodes a peptide of 35 amino acids, and is co-transcribed with spyA. Expression of spyBA is strongly influenced by translational coupling: mutational inactivation of spyB translation completely abolishes translation of spyA. spyB expression increases with increasing cell density and reaches its maximum at late exponential growth phase. The SpyB N-terminus is predicted to fold into an amphipathic α-helix, a structural motif that targets a protein to the cytoplasmic membrane. Consistent with the prediction, we found that a SpyB fusion with peptide affinity tags is located in the streptococcal membrane. An ADP-ribosylation assay with recombinant SpyA demonstrated that SpyA modifies SpyB. Thus, our study suggests that ADP-ribosylation of SpyB may be an important function of SpyA.
Author List
Korotkova N, Hoff JS, Becker DM, Quinn JK, Icenogle LM, Moseley SLAuthor
Jessica Hoff PhD Assistant Professor in the Pathology department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
ADP Ribose TransferasesBacterial Proteins
DNA, Bacterial
Gene Expression Regulation, Bacterial
Membrane Proteins
Mutagenesis, Site-Directed
Operon
Plasmids
Protein Structure, Secondary
Streptococcus pyogenes
Virulence Factors
