1IZK

Thermoactinomyces vulgaris R-47 alpha-amylase 1 mutant enzyme w398v

Summary for 1IZK

• Entry DOI: 10.2210/pdb1izk/pdb
• Related: 1IZJ 1JI1
• Descriptor: amylase, CALCIUM ION (3 entities in total)
• Functional Keywords: alpha-beta barrele, hydrolase
• Biological source: Thermoactinomyces vulgaris
• Cellular location: Secreted: Q60053
• Total number of polymer chains: 1
• Total formula weight: 71143.44

Authors

Ohtaki, A.,Iguchi, A.,Mizuno, M.,Tonozuka, T.,Sakano, Y.,Kamitori, S. (deposition date: 2002-10-03, release date: 2003-07-29, Last modification date: 2023-12-27)

Primary citation

Ohtaki, A.,Iguchi, A.,Mizuno, M.,Tonozuka, T.,Sakano, Y.,Kamitori, S.
Mutual conversion of substrate specificities of Thermoactinomyces vulgaris R-47 alpha-amylases TVAI and TVAII by site-directed mutagenesis
CARBOHYDR.RES., 338:1553-1558, 2003

PubMed Abstract: Thermoactinomyces vulgaris R-47 produces two alpha-amylases, TVAI and TVAII, differing in substrate specificity from each other. TVAI favors high-molecular-weight substrates like starch, and scarcely hydrolyzes cyclomaltooligosaccharides (cyclodextrins) with a small cavity. TVAII favors low-molecular-weight substrates like oligosaccharides, and can efficiently hydrolyze cyclodextrins with various sized cavities. To understand the relationship between the structure and substrate specificity of these enzymes, we precisely examined the roles of key residues for substrate recognition by X-ray structural and kinetic parameter analyses of mutant enzymes and successfully obtained mutants in which the substrate specificity of each enzyme is partially converted into that of another.

PubMed: 12860426
DOI: 10.1016/S0008-6215(03)00219-2

Experimental method

X-RAY DIFFRACTION (2.2 Å)