SclA, a novel collagen-like surface protein of Streptococcus pyogenes
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TL;DR: Preliminary phylogenetic analysis indicates that horizontal gene transfer has contributed to the evolution of sclA, a novel collagen-like surface protein of Streptococcus pyogenes found to be positively regulated by Mga and shared with the M protein of S. pyogene.
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Abstract: Surface proteins of Streptococcus pyogenes are important virulence factors. Here we describe a novel collagen-like surface protein, designated SclA (streptococcal collagen-like surface protein). The sclA gene was identified in silico using the Streptococcal Genome Sequencing Project with the recently identified protein GRAB as the probe. SclA has a signal sequence and a cell wall attachment region containing the prototypic LPXTGX motif. The surface-exposed part of SclA contains a unique NH(2)-terminal domain of 73 amino acids, followed by a collagen-like region. The sclA gene was found to be positively regulated by Mga, a transcriptional activator of several S. pyogenes virulence determinants. A mutant lacking cell wall-associated SclA was constructed and was found to be as effective as wild-type bacteria in platelet aggregation, survival in fresh human blood, and adherence to pharyngeal cells. The sclA gene was found in all 12 S. pyogenes strains that were investigated using PCR. Sequence analysis revealed that the signal sequence and the cell wall attachment region are highly conserved. The collagen-like domain is variable in its NH(2)-terminal region and has conserved repeated domains in its COOH-terminal part. SclA proteins from most strains have additional proline-rich repeats spacing the collagen-like domain and the cell wall attachment sequence. The unique NH(2)-terminal region is hypervariable, but computer predictions indicate a common secondary structure, with two alpha helices connected by a loop region. Immune selection may explain the hypervariability in the NH(2)-terminal region, whereas the preserved secondary structure implies that this region has a common function. These features and the Mga regulation are shared with the M protein of S. pyogenes. Moreover, as with the gene encoding the M protein, phylogenetic analysis indicates that horizontal gene transfer has contributed to the evolution of sclA.
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Citations
Disease Manifestations and Pathogenic Mechanisms of Group A Streptococcus
Mark J. Walker,Timothy C. Barnett,Jason D. McArthur,Jason N. Cole,Jason N. Cole,Christine M. Gillen,Anna Henningham,Anna Henningham,Kadaba S. Sriprakash,Martina L. Sanderson-Smith,Victor Nizet,Victor Nizet +11 more
TL;DR: Genomic and molecular analyses have now characterized a large number of GAS virulence determinants, many of which exhibit overlap and redundancy in the processes of adhesion and colonization, innate immune resistance, and the capacity to facilitate tissue barrier degradation and spread within the human host.
Streptococcus Adherence and Colonization
TL;DR: There is much focus on applying increasingly advanced molecular techniques to determine the precise structures and functions of these proteins, and their regulatory pathways, so that more targeted approaches can be developed against streptococcal infections.
660
The interaction of bacterial pathogens with platelets.
TL;DR: The nature of the interactions between platelets and bacteria, and the role of these interactions in the pathogenesis of endocarditis and other cardiovascular diseases are reviewed.
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Platelets in defense against bacterial pathogens
TL;DR: The molecular and cellular roles of platelets in host defense against bacterial pathogens are explored with attention on advances in platelet immunobiology.
Streptococcal Scl1 and Scl2 proteins form collagen-like triple helices
TL;DR: It is demonstrated by electron microscopy that the Scl proteins are organized into “lollipop-like” structures, similar to those seen in human proteins with collagenous domains, which implies that the repeated GXY tripeptide motif is a structural indicator of collagen-like triple helices in proteins from such phylogenetically distant sources as bacteria and humans.
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References
•Book
Molecular cloning : a laboratory manual
Joseph Sambrook,David W. Russell +1 more
- 01 Jan 2001
TL;DR: The content has been entirely recast to include nucleic-acid based methods selected as the most widely used and valuable in molecular and cellular biology laboratories.
126.4K
Identification of prokaryotic and eukaryotic signal peptides and prediction of their cleavage sites.
TL;DR: A new method for the identification of signal peptides and their cleavage sites based on neural networks trained on separate sets of prokaryotic and eukaryotic sequence that performs significantly better than previous prediction schemes and can easily be applied on genome-wide data sets.
SHORT COMMUNICATION Identification of prokaryotic and eukaryotic signal peptides and prediction of their cleavage sites
Henrik Nielsen,Jacob Engelbrecht,Søren Brunak +2 more
- 01 Jan 1997
TL;DR: In this paper, a new method for the identification of in performance compared with the weight matrix method signal peptides and their cleavage sites based on neural (Arrigo et al., 1991; Ladunga et al, 1991; Schneider and networks trained on separate sets of prokaryotic and eukaryotic sequence.
5.2K
Analysis of the accuracy and implications of simple methods for predicting the secondary structure of globular proteins.
TL;DR: The algorithm is shown to be at least as good as, and usually superior to, the reported prediction methods assessed in the same way and the implication in protein folding is discussed.
4.6K