3FP8

Anionic trypsin variant S195A in complex with bovine pancreatic trypsin inhibitor (BPTI) determined to the 1.46 A resolution limit

Summary for 3FP8

• Entry DOI: 10.2210/pdb3fp8/pdb
• Related: 3FP6 3FP7 3TGI
• Descriptor: Anionic trypsin-2, Pancreatic trypsin inhibitor, 1,2-ETHANEDIOL, ... (7 entities in total)
• Functional Keywords: enzyme-inhibitor complex, peptide bond hydrolysis, serine protease, calcium, digestion, hydrolase, metal-binding, protease, secreted, zymogen, pharmaceutical, protease inhibitor, serine protease inhibitor, hydrolase-hydrolase inhibitor complex, hydrolase/hydrolase inhibitor
• Biological source: Rattus norvegicus (brown rat,rat,rats); More
• Cellular location: Secreted, extracellular space: P00763; Secreted: P00974
• Total number of polymer chains: 2
• Total formula weight: 31317.37

Authors

Zakharova, E.,Horvath, M.P.,Goldenberg, D.P.,Curtice, K. (deposition date: 2009-01-04, release date: 2009-02-17, Last modification date: 2024-10-16)

Primary citation

Zakharova, E.,Horvath, M.P.,Goldenberg, D.P.
Structure of a serine protease poised to resynthesize a peptide bond.
Proc.Natl.Acad.Sci.USA, 106:11034-11039, 2009

PubMed Abstract: The serine proteases are among the most thoroughly studied enzymes, and numerous crystal structures representing the enzyme-substrate complex and intermediates in the hydrolysis reactions have been reported. Some aspects of the catalytic mechanism remain controversial, however, especially the role of conformational changes in the reaction. We describe here a high-resolution (1.46 A) crystal structure of a complex formed between a cleaved form of bovine pancreatic trypsin inhibitor (BPTI) and a catalytically inactive trypsin variant with the BPTI cleavage site ideally positioned in the active site for resynthesis of the peptide bond. This structure defines the positions of the newly generated amino and carboxyl groups following the 2 steps in the hydrolytic reaction. Comparison of this structure with those representing other intermediates in the reaction demonstrates that the residues of the catalytic triad are positioned to promote each step of both the forward and reverse reaction with remarkably little motion and with conservation of hydrogen-bonding interactions. The results also provide insights into the mechanism by which inhibitors like BPTI normally resist hydrolysis when bound to their target proteases.

PubMed: 19549826
DOI: 10.1073/pnas.0902463106

Experimental method

X-RAY DIFFRACTION (1.46 Å)