The crystal structure of the streptococcal collagen-like protein 2 globular domain from invasive M3-type group a streptococcus shows significant similarity to immunomodulatory HIV protein gp41

Background: Streptococcal collagen-like proteins play crucial roles in host adhesion, host cell entry, and immunomodulation of host defenses. Results: This study provides the first three-dimensional structural description of a streptococcal collagen-like protein. Conclusion: The crystal structure evidences a six-helical bundle fold, which is unusual in bacterial proteins and characteristic of viral fusion proteins. Significance: The high resolution structure provides a structural basis for the design of inhibitors of streptococcal invasion. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.