1AK9

SUBTILISIN MUTANT 8321

DOI: 10.2210/pdb1AK9/pdb

Classification: SERINE PROTEASE
Organism(s): Bacillus amyloliquefaciens
Expression System: Bacillus subtilis
Mutation(s): Yes

Deposited: 1997-05-30 Released: 1997-11-12
Deposition Author(s): Whitlow, M., Howard, A.J., Wood, J.F.

Experimental Data Snapshot

Method: X-RAY DIFFRACTION
Resolution: 1.80 Å
R-Value Work: 0.148

wwPDB Validation 3D Report Full Report

This is version 1.2 of the entry. See complete history.

Literature

Large increases in general stability for subtilisin BPN' through incremental changes in the free energy of unfolding.

Pantoliano, M.W., Whitlow, M., Wood, J.F., Dodd, S.W., Hardman, K.D., Rollence, M.L., Bryan, P.N.

(1989) Biochemistry 28: 7205-7213

PubMed: 2684274 Search on PubMed
DOI: 10.1021/bi00444a012
Primary Citation of Related Structures:
1A2Q, 1AK9, 1AU9, 1S01

PubMed Abstract:

Six individual amino acid substitutions at separate positions in the tertiary structure of subtilisin BPN' (EC 3.4.21.14) were found to increase the stability of this enzyme, as judged by differential scanning calorimetry and decreased rates of thermal inactivation. These stabilizing changes, N218S, G169A, Y217K, M50F, Q206C, and N76D, were discovered through the use of five different investigative approaches: (1) random mutagenesis; (2) design of buried hydrophobic side groups; (3) design of electrostatic interactions at Ca2+ binding sites; (4) sequence homology consensus; and (5) serendipity. Individually, the six amino acid substitutions increase the delta G of unfolding between 0.3 and 1.3 kcal/mol at 58.5 degrees C. The combination of these six individual stabilizing mutations together into one subtilisin BPN' molecule was found to result in approximately independent and additive increases in the delta G of unfolding to give a net increase of 3.8 kcal/mol (58.5 degrees C). Thermodynamic stability was also shown to be related to resistance to irreversible inactivation, which included elevated temperatures (65 degrees C) or extreme alkalinity (pH 12.0). Under these denaturing conditions, the rate of inactivation of the combination variant is approximately 300 times slower than that of the wild-type subtilisin BPN'. A comparison of the 1.8-A-resolution crystal structures of mutant and wild-type enzymes revealed only independent and localized structural changes around the site of the amino acid side group substitutions.(ABSTRACT TRUNCATED AT 250 WORDS)

Related Citations:

The Engineering of Binding Affinity at Metal Ion Binding Sites for the Stabilization of Proteins: Subtilisin as a Test Case
Pantoliano, M.W., Whitlow, M., Wood, J.F., Rollence, M.L., Finzel, B.C., Gilliland, G.L., Poulos, T.L., Bryan, P.N.
(1988) Biochemistry 27: 8311

Protein Engineering of Subtilisin Bpn': Enhanced Stabilization Through the Introduction of Two Cysteines to Form a Disulfide Bond
Pantoliano, M.W., Ladner, R.C., Bryan, P.N., Rollence, M.L., Wood, J.F., Poulos, T.L.
(1987) Biochemistry 26: 2077

Proteases of Enhanced Stability: Characterization of a Thermostable Variant of Subtilisin
Bryan, P.N., Rollence, M.L., Pantoliano, M.W., Wood, J., Finzel, B.C., Gilliland, G.L., Howard, A.J., Poulos, T.L.
(1986) Proteins 1: 326

Atomic Coordinates for Subtilisin Bpn' (or Novo)
Alden, R.A., Birktoft, J.J., Kraut, J., Robertus, J.D., Wright, C.S.
(1971) Biochem Biophys Res Commun 45: 337

Organizational Affiliation:

Genex Corporation, Gaithersburg, Maryland 20877.

Macromolecules

Find similar proteins by:

(by identity cutoff) | Structure

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
SUBTILISIN 8321	A	275	Bacillus amyloliquefaciens	Mutation(s): 6 Gene Names: apr EC: 3.4.21.62
UniProt
Find proteins for P00782 (Bacillus amyloliquefaciens) Explore P00782 Go to UniProtKB: P00782
Protein Feature View Expand
Reference Sequence

Small Molecules

Ligands 3 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram	3D Interactions
IPA Query on IPA Download Ideal Coordinates CCD File SDF format, chain E [auth A] SDF format, chain F [auth A] MOL2 format, chain E [auth A] MOL2 format, chain F [auth A]	E [auth A], F [auth A]	ISOPROPYL ALCOHOL C₃ H₈ O KFZMGEQAYNKOFK-UHFFFAOYSA-N		Ligand Interaction
CA Query on CA Download Ideal Coordinates CCD File SDF format, chain B [auth A] SDF format, chain D [auth A] MOL2 format, chain B [auth A] MOL2 format, chain D [auth A]	B [auth A], D [auth A]	CALCIUM ION Ca BHPQYMZQTOCNFJ-UHFFFAOYSA-N		Ligand Interaction
NA Query on NA Download Ideal Coordinates CCD File SDF format, chain C [auth A] MOL2 format, chain C [auth A]	C [auth A]	SODIUM ION Na FKNQFGJONOIPTF-UHFFFAOYSA-N		Ligand Interaction