6JFJ

Crystal structure of Pullulanase from Paenibacillus barengoltzii complex with maltohexaose and alpha-cyclodextrin

Replaces:  5WW2

Summary for 6JFJ

• Entry DOI: 10.2210/pdb6jfj/pdb
• Related: 6JEQ
• Related PRD ID: PRD_900009 PRD_900030
• Descriptor: Pulullanase, CALCIUM ION, CHLORIDE ION, ... (12 entities in total)
• Functional Keywords: gh13, pullulanase, alpha-cyclodextrin, maltohexaose, hydrolase
• Biological source: Paenibacillus barengoltzii
• Total number of polymer chains: 1
• Total formula weight: 79955.95

Authors

Wu, S.W.,Yang, S.Q.,Qin, Z.,You, X.,Huang, P.,Jiang, Z.Q. (deposition date: 2019-02-09, release date: 2019-02-20, Last modification date: 2023-11-22)

Primary citation

Huang, P.,Wu, S.,Yang, S.,Yan, Q.,Jiang, Z.
Structural basis of carbohydrate binding in domain C of a type I pullulanase from Paenibacillus barengoltzii.
Acta Crystallogr D Struct Biol, 76:447-457, 2020

PubMed Abstract: Pullulanase (EC 3.2.1.41) is a well known starch-debranching enzyme that catalyzes the cleavage of α-1,6-glycosidic linkages in α-glucans such as starch and pullulan. Crystal structures of a type I pullulanase from Paenibacillus barengoltzii (PbPulA) and of PbPulA in complex with maltopentaose (G5), maltohexaose (G6)/α-cyclodextrin (α-CD) and β-cyclodextrin (β-CD) were determined in order to better understand substrate binding to this enzyme. PbPulA belongs to glycoside hydrolase (GH) family 13 subfamily 14 and is composed of three domains (CBM48, A and C). Three carbohydrate-binding sites identified in PbPulA were located in CBM48, near the active site and in domain C, respectively. The binding site in CBM48 was specific for β-CD, while that in domain C has not been reported for other pullulanases. The domain C binding site had higher affinity for α-CD than for G6; a small motif (FGGEH) seemed to be one of the major determinants for carbohydrate binding in this domain. Structure-based mutations of several surface-exposed aromatic residues in CBM48 and domain C had a debilitating effect on the activity of the enzyme. These results suggest that both CBM48 and domain C play a role in binding substrates. The crystal forms described contribute to the understanding of pullulanase domain-carbohydrate interactions.

PubMed: 32355041
DOI: 10.1107/S205979832000409X

Experimental method

X-RAY DIFFRACTION (1.932 Å)