1GNV

CALCIUM INDEPENDENT SUBTILISIN BPN' MUTANT

Summary for 1GNV

• Entry DOI: 10.2210/pdb1gnv/pdb
• Related: 1A2Q 1AK9 1AQN 1AU9 1GNS 1S01 1S02 1SBH 1SBI 1SBN 1SBT 1SIB 1SPB 1ST2 1SUA 1SUB 1SUC 1SUD 1SUE 1SUP 1UBN 1YJA 1YJB 1YJC 2SBT 2SIC 2SNI 2ST1 3SIC 5SIC
• Descriptor: SUBTILISIN BPN' (2 entities in total)
• Functional Keywords: hydrolase, serine proteinase
• Biological source: BACILLUS AMYLOLIQUEFACIENS
• Cellular location: Secreted: P00782
• Total number of polymer chains: 1
• Total formula weight: 26771.63

Authors

Almog, O.,Gilliland, G.L. (deposition date: 2001-10-10, release date: 2002-06-24, Last modification date: 2023-12-13)

Primary citation

Almog, O.,Gallagher, D.T.,Ladner, J.E.,Strausberg, S.,Alexander, P.,Bryan, P.,Gilliland, G.L.
Structural Basis of Thermostability. Analysis of Stabilizing Mutations in Subtilisin Bpn'.
J.Biol.Chem., 277:27553-, 2002

PubMed Abstract: The crystal structures of two thermally stabilized subtilisin BPN' variants, S63 and S88, are reported here at 1.8 and 1.9 A resolution, respectively. The micromolar affinity calcium binding site (site A) has been deleted (Delta75-83) in these variants, enabling the activity and thermostability measurements in chelating conditions. Each of the variants includes mutations known previously to increase the thermostability of calcium-independent subtilisin in addition to new stabilizing mutations. S63 has eight amino acid replacements: D41A, M50F, A73L, Q206W, Y217K, N218S, S221C, and Q271E. S63 has 75-fold greater stability than wild type subtilisin in chelating conditions (10 mm EDTA). The other variant, S88, has ten site-specific changes: Q2K, S3C, P5S, K43N, M50F, A73L, Q206C, Y217K, N218S, and Q271E. The two new cysteines form a disulfide bond, and S88 has 1000 times greater stability than wild type subtilisin in chelating conditions. Comparisons of the two new crystal structures (S63 in space group P2(1) with A cell constants 41.2, 78.1, 36.7, and beta = 114.6 degrees and S88 in space group P2(1)2(1)2(1) with cell constants 54.2, 60.4, and 82.7) with previous structures of subtilisin BPN' reveal that the principal changes are in the N-terminal region. The structural bases of the stabilization effects of the new mutations Q2K, S3C, P5S, D41A, Q206C, and Q206W are generally apparent. The effects are attributed to the new disulfide cross-link and to improved hydrophobic packing, new hydrogen bonds, and other rearrangements in the N-terminal region.

PubMed: 12011071
DOI: 10.1074/JBC.M111777200

Experimental method

X-RAY DIFFRACTION (1.9 Å)