4D8B

High resolution structure of monomeric S. progenies SpeB reveals role of glycine-rich active site loop

Summary for 4D8B

• Entry DOI: 10.2210/pdb4d8b/pdb
• Related: 1DKI 2JTC 2UZJ 4D8E 4D8I
• Descriptor: Streptopain, NITRATE ION (3 entities in total)
• Functional Keywords: papain fold, cysteine protease, secreted, hydrolase
• Biological source: Streptococcus pyogenes
• Total number of polymer chains: 1
• Total formula weight: 28743.70

Authors

Gonzalez, G.E.,Wolan, D.W. (deposition date: 2012-01-10, release date: 2012-06-06, Last modification date: 2024-02-28)

Primary citation

Gonzalez-Paez, G.E.,Wolan, D.W.
Ultrahigh and High Resolution Structures and Mutational Analysis of Monomeric Streptococcus pyogenes SpeB Reveal a Functional Role for the Glycine-rich C-terminal Loop.
J.Biol.Chem., 287:24412-24426, 2012

PubMed Abstract: Cysteine protease SpeB is secreted from Streptococcus pyogenes and has been studied as a potential virulence factor since its identification almost 70 years ago. Here, we report the crystal structures of apo mature SpeB to 1.06 Å resolution as well as complexes with the general cysteine protease inhibitor trans-epoxysuccinyl-l-leucylamido(4-guanidino)butane and a novel substrate mimetic peptide inhibitor. These structures uncover conformational changes associated with maturation of SpeB from the inactive zymogen to its active form and identify the residues required for substrate binding. With the use of a newly developed fluorogenic tripeptide substrate to measure SpeB activity, we determined IC(50) values for trans-epoxysuccinyl-l-leucylamido(4-guanidino)butane and our new peptide inhibitor and the effects of mutations within the C-terminal active site loop. The structures and mutational analysis suggest that the conformational movements of the glycine-rich C-terminal loop are important for the recognition and recruitment of biological substrates and release of hydrolyzed products.

PubMed: 22645124
DOI: 10.1074/jbc.M112.361576

Experimental method

X-RAY DIFFRACTION (1.058 Å)