6JQB

The structure of maltooligosaccharide-forming amylase from Pseudomonas saccharophila STB07 with pseudo-maltoheptaose

Summary for 6JQB

• Entry DOI: 10.2210/pdb6jqb/pdb
• Descriptor: Glucan 1,4-alpha-maltotetraohydrolase, 1,2-ETHANEDIOL, CALCIUM ION, ... (5 entities in total)
• Functional Keywords: maltooligosaccharide-forming amylase, saccharophila stb07, sugar binding protein, hydrolase
• Biological source: Pelomonas saccharophila
• Total number of polymer chains: 1
• Total formula weight: 59109.20

Authors

Li, Z.F.,Ban, X.F.,Zhang, Z.Q.,Li, C.M.,Gu, Z.B.,Jin, T.C.,Li, Y.L.,Shang, Y.H. (deposition date: 2019-03-30, release date: 2020-04-01, Last modification date: 2024-10-09)

Primary citation

Zhang, Z.,Jin, T.,Xie, X.,Ban, X.,Li, C.,Hong, Y.,Cheng, L.,Gu, Z.,Li, Z.
Structure of maltotetraose-forming amylase from Pseudomonas saccharophila STB07 provides insights into its product specificity.
Int.J.Biol.Macromol., 154:1303-1313, 2020

PubMed Abstract: The maltooligosaccharide-forming amylases (MFAses) degrade starch into maltooligosaccharides which potentially benefit human diet and grow popular in food processing, but little has been studied about their product specificity and structures. We focused on this topic and provide evidence through an X-ray crystal structure of the maltotetraose (G4)-forming amylase from Pseudomonas saccharophila STB07 (MFA), as well as co-crystal structures of MFA with G4 and with pseudo-maltoheptaose (pseudo-G7) determined at up to 1.1 Å resolution. G4 and pseudo-G7 occupy active cleft subsites -4 to -1 and -4 to +3 respectively. Binding induces conformational changes in the active sites except Asp193, working as the base catalyst. Comparison of the MFA structure with those of other α-amylases revealed obvious differences in the loop structures providing dominant interactions between protein and substrate in the non-reducing side of the active sites cleft. These structures at the non-reducing end may govern the G4 specificity of MFA and also be relevant to its exo-type action pattern.

PubMed: 31751711
DOI: 10.1016/j.ijbiomac.2019.11.006

Experimental method

X-RAY DIFFRACTION (1.101 Å)