Open AccessMolecular analysis of cyclic α-maltosyl-(1→6)-maltose binding protein in the bacterial metabolic pathway
Author(s) -
Masanori Kohno,
T. Arakawa,
Naoki Sunagawa,
Tetsuya Mori,
Kiyohiko Igarashi,
Tetsuya Nishimoto,
Shinya Fushinobu
Publication year - 2020
Publication title -
plos one
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.99
H-Index - 332
ISSN - 1932-6203
DOI - 10.1371/journal.pone.0241912
Subject(s) - isothermal titration calorimetry , chemistry , maltose , biochemistry , arthrobacter , plasma protein binding , protein structure , substrate (aquarium) , crystal structure , hydrolase , crystallography , stereochemistry , enzyme , biology , ecology
Cyclic α-maltosyl-(1→6)-maltose (CMM) is a cyclic glucotetrasaccharide with alternating α-1,4 and α-1,6 linkages. Here, we report functional and structural analyses on CMM-binding protein (CMMBP), which is a substrate-binding protein (SBP) of an ABC importer system of the bacteria Arthrobacter globiformis . Isothermal titration calorimetry analysis revealed that CMMBP specifically bound to CMM with a K d value of 9.6 nM. The crystal structure of CMMBP was determined at a resolution of 1.47 Å, and a panose molecule was bound in a cleft between two domains. To delineate its structural features, the crystal structure of CMMBP was compared with other SBPs specific for carbohydrates, such as cyclic α-nigerosyl-(1→6)-nigerose and cyclodextrins. These results indicate that A . globiformis has a unique metabolic pathway specialized for CMM.