1G6X

ULTRA HIGH RESOLUTION STRUCTURE OF BOVINE PANCREATIC TRYPSIN INHIBITOR (BPTI) MUTANT WITH ALTERED BINDING LOOP SEQUENCE

Summary for 1G6X

• Entry DOI: 10.2210/pdb1g6x/pdb
• Related: 1AAL 1BPT 1BTI 1FAN 1QLQ 4PTI 5PTI 6PTI 7PTI 8PTI 9PTI
• Descriptor: PANCREATIC TRYPSIN INHIBITOR, SULFATE ION, 1,2-ETHANEDIOL, ... (4 entities in total)
• Functional Keywords: serine protease inhibitor, hydrolase inhibitor
• Biological source: Bos taurus (cattle)
• Cellular location: Secreted: P00974
• Total number of polymer chains: 1
• Total formula weight: 7374.12

Authors

Addlagatta, A.,Czapinska, H.,Krzywda, S.,Otlewski, J.,Jaskolski, M. (deposition date: 2000-11-08, release date: 2001-05-09, Last modification date: 2024-11-06)

Primary citation

Addlagatta, A.,Krzywda, S.,Czapinska, H.,Otlewski, J.,Jaskolski, M.
Ultrahigh-resolution structure of a BPTI mutant.
Acta Crystallogr.,Sect.D, 57:649-663, 2001

PubMed Abstract: The crystal structure of a mutant of bovine pancreatic trypsin inhibitor has been refined to 0.86 A resolution using low-temperature synchrotron data. The variant contains three mutations in the binding loop (Thr11Ala, Pro13Ala, Lys15Arg) and an unrelated Met52Leu substitution. Refinement with anisotropic displacement parameters and with removal of main-chain stereochemical restraints converged with R = 0.1035. The use of full-matrix refinement provided an estimate of the variances in the derived parameters. Some stereochemical parameters, such as the planarity of the peptide group and the value of the N-C(alpha)-C angle, show a wide spread, suggesting that the standard values used as restraints in protein structure refinements may not always be entirely appropriate. Comparison with the recently determined room-temperature structure of the same mutant at 1.42 A resolution confirms the previous observations and provides new details, such as a double conformation of the main chain at Leu29 and at Gly56-Gly57, a high proportion (over 20%) of residues in double conformations, correlation of disorder through lattice contacts and the positions of H atoms, including those in water molecules, and their involvement in C-H...O and N-H...pi hydrogen bonds.

PubMed: 11320305
DOI: 10.1107/S0907444901003468

Experimental method

X-RAY DIFFRACTION (0.86 Å)