Unknown

Dataset Information

0

Thermus thermophilus glycoside hydrolase family 57 branching enzyme: crystal structure, mechanism of action, and products formed.


ABSTRACT: Branching enzyme (EC 2.4.1.18; glycogen branching enzyme; GBE) catalyzes the formation of ?1,6-branching points in glycogen. Until recently it was believed that all GBEs belong to glycoside hydrolase family 13 (GH13). Here we describe the cloning and expression of the Thermus thermophilus family GH57-type GBE and report its biochemical properties and crystal structure at 1.35-? resolution. The enzyme has a central (?/?)(7)-fold catalytic domain A with an inserted domain B between ?2 and ?5 and an ?-helix-rich C-terminal domain, which is shown to be essential for substrate binding and catalysis. A maltotriose was modeled in the active site of the enzyme which suggests that there is insufficient space for simultaneously binding of donor and acceptor substrates, and that the donor substrate must be cleaved before acceptor substrate can bind. The biochemical assessment showed that the GH57 GBE possesses about 4% hydrolytic activity with amylose and in vitro forms a glucan product with a novel fine structure, demonstrating that the GH57 GBE is clearly different from the GH13 GBEs characterized to date.

SUBMITTER: Palomo M 

PROVIDER: S-EPMC3030357 | biostudies-literature | 2011 Feb

REPOSITORIES: biostudies-literature

altmetric image

Publications

Thermus thermophilus glycoside hydrolase family 57 branching enzyme: crystal structure, mechanism of action, and products formed.

Palomo Marta M   Pijning Tjaard T   Booiman Thijs T   Dobruchowska Justyna M JM   van der Vlist Jeroen J   Kralj Slavko S   Planas Antoni A   Loos Katja K   Kamerling Johannis P JP   Dijkstra Bauke W BW   van der Maarel Marc J E C MJ   Dijkhuizen Lubbert L   Leemhuis Hans H  

The Journal of biological chemistry 20101119 5


Branching enzyme (EC 2.4.1.18; glycogen branching enzyme; GBE) catalyzes the formation of α1,6-branching points in glycogen. Until recently it was believed that all GBEs belong to glycoside hydrolase family 13 (GH13). Here we describe the cloning and expression of the Thermus thermophilus family GH57-type GBE and report its biochemical properties and crystal structure at 1.35-Å resolution. The enzyme has a central (β/α)(7)-fold catalytic domain A with an inserted domain B between β2 and α5 and a  ...[more]

Similar Datasets

| S-EPMC9291813 | biostudies-literature
| S-EPMC4453472 | biostudies-literature
| S-EPMC2344104 | biostudies-literature
| S-EPMC4246079 | biostudies-literature
| S-EPMC3606586 | biostudies-literature
| S-EPMC18352 | biostudies-literature
| S-EPMC2614558 | biostudies-literature
| S-EPMC1183492 | biostudies-literature
| S-EPMC434449 | biostudies-literature
| S-EPMC3911032 | biostudies-literature