2D3L

Crystal structure of maltohexaose-producing amylase from Bacillus sp.707 complexed with maltopentaose.

Summary for 2D3L

• Entry DOI: 10.2210/pdb2d3l/pdb
• Related: 1WP6 1WPC 2D3N
• Related PRD ID: PRD_900009 PRD_900030
• Descriptor: Glucan 1,4-alpha-maltohexaosidase, alpha-D-glucopyranose-(1-4)-alpha-D-glucopyranose-(1-4)-alpha-D-glucopyranose-(1-4)-alpha-D-glucopyranose-(1-4)-alpha-D-glucopyranose, alpha-D-glucopyranose-(1-4)-alpha-D-glucopyranose-(1-4)-alpha-D-glucopyranose, ... (7 entities in total)
• Functional Keywords: protein-carbohydrate complex, ligand binding, hydrolase
• Biological source: Bacillus sp.
• Total number of polymer chains: 1
• Total formula weight: 57275.58

Authors

Kanai, R.,Haga, K.,Akiba, T.,Yamane, K.,Harata, K. (deposition date: 2005-09-29, release date: 2006-03-14, Last modification date: 2023-10-25)

Primary citation

Kanai, R.,Haga, K.,Akiba, T.,Yamane, K.,Harata, K.
Role of Trp140 at subsite -6 on the maltohexaose production of maltohexaose-producing amylase from alkalophilic Bacillus sp.707
Protein Sci., 15:468-477, 2006

PubMed Abstract: Maltohexaose-producing amylase (G6-amylase) from alkalophilic Bacillus sp.707 predominantly produces maltohexaose (G6) in the yield of >30% of the total products from short-chain amylose (DP=17). Our previous crystallographic study showed that G6-amylase has nine subsites, from -6 to +3, and pointed out the importance of the indole moiety of Trp140 in G6 production. G6-amylase has very low levels of hydrolytic activities for oligosaccharides shorter than maltoheptaose. To elucidate the mechanism underlying G6 production, we determined the crystal structures of the G6-amylase complexes with G6 and maltopentaose (G5). In the active site of the G6-amylase/G5 complex, G5 is bound to subsites -6 to -2, while G1 and G6 are found at subsites +2 and -7 to -2, respectively, in the G6-amylase/G6 complex. In both structures, the glucosyl residue located at subsite -6 is stacked to the indole moiety of Trp140 within a distance of 4A. The measurement of the activities of the mutant enzymes when Trp140 was replaced by leucine (W140L) or by tyrosine (W140Y) showed that the G6 production from short-chain amylose by W140L is lower than that by W140Y or wild-type enzyme. The face-to-face short contact between Trp140 and substrate sugars is suggested to regulate the disposition of the glucosyl residue at subsite -6 and to govern product specificity for G6 production.

PubMed: 16452622
DOI: 10.1110/ps.051877006

Experimental method

X-RAY DIFFRACTION (2.3 Å)