4H2C

Trehalulose synthase MutB R284C mutant

Summary for 4H2C

• Entry DOI: 10.2210/pdb4h2c/pdb
• Related: 1ZJA 1ZJB 2PWD 2PWE 2PWF 2PWG 2PWH 4GI6 4GI8 4GI9 4GIA 4GIN
• Descriptor: Sucrose isomerase, CALCIUM ION, GLYCEROL, ... (4 entities in total)
• Functional Keywords: mutant enzyme, tim-barrel, (beta/alpha)8, sucrose isomerase, glycoside hydrolase, trehalulose synthase, gh13 family(cazy database), calcium binding, isomerase
• Biological source: Rhizobium
• Total number of polymer chains: 1
• Total formula weight: 64385.34

Authors

Lipski, A.,Ravaud, S.,Robert, X.,Haser, R.,Aghajari, N. (deposition date: 2012-09-12, release date: 2013-02-13, Last modification date: 2023-11-08)

Primary citation

Lipski, A.,Watzlawick, H.,Ravaud, S.,Robert, X.,Rhimi, M.,Haser, R.,Mattes, R.,Aghajari, N.
Mutations inducing an active-site aperture in Rhizobium sp. sucrose isomerase confer hydrolytic activity
Acta Crystallogr.,Sect.D, 69:298-307, 2013

PubMed Abstract: Sucrose isomerase is an enzyme that catalyzes the production of sucrose isomers of high biotechnological and pharmaceutical interest. Owing to the complexity of the chemical synthesis of these isomers, isomaltulose and trehalulose, enzymatic conversion remains the preferred method for obtaining these products. Depending on the microbial source, the ratio of the sucrose-isomer products varies significantly. In studies aimed at understanding and explaining the underlying molecular mechanisms of these reactions, mutations obtained using a random-mutagenesis approach displayed a major hydrolytic activity. Two of these variants, R284C and F164L, of sucrose isomerase from Rhizobium sp. were therefore crystallized and their crystal structures were determined. The three-dimensional structures of these mutants allowed the identification of the molecular determinants that favour hydrolytic activity compared with transferase activity. Substantial conformational changes resulting in an active-site opening were observed, as were changes in the pattern of water molecules bordering the active-site region.

PubMed: 23385465
DOI: 10.1107/S0907444912045532

Experimental method

X-RAY DIFFRACTION (1.7 Å)