Cullen R, Teçza M, Miclot T, Behan S, Jain M, Avink MK, Cooney JC, Kagawa TF. The 1.7 Å crystal structure of the C5a peptidase from Streptococcus agalactiae (ScpB) reveals an active site competent for catalysis.
Proteins 2024;
92:427-431. [PMID:
37921533 DOI:
10.1002/prot.26625]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Revised: 10/02/2023] [Accepted: 10/17/2023] [Indexed: 11/04/2023]
Abstract
A 1.7 Å structure is presented for an active form of the virulence factor ScpB, the C5a peptidase from Streptococcus agalactiae. The previously reported structure of the ScpB active site mutant exhibited a large separation (~20 Å) between the catalytic His and Ser residues. Significant differences are observed in the catalytic domain between the current and mutant ScpB structures resulting with a high RMSDCα (4.6 Å). The fold of the active form of ScpB is nearly identical to ScpA (RMSDCα 0.2 Å), the C5a-peptidase from Streptococcus pyogenes. Both ScpA and ScpB have comparable activity against human C5a, indicating neither enzyme require host proteins for C5a-ase activity. These studies are a first step in resolving reported differences in the specificities of these enzymes.
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