1SQJ

Crystal Structure Analysis of Oligoxyloglucan reducing-end-specific cellobiohydrolase (OXG-RCBH)

Summary for 1SQJ

• Entry DOI: 10.2210/pdb1sqj/pdb
• Descriptor: oligoxyloglucan reducing-end-specific cellobiohydrolase (2 entities in total)
• Functional Keywords: beta-propeller, hydrolase
• Biological source: Geotrichum sp. M128
• Total number of polymer chains: 2
• Total formula weight: 169949.45

Authors

Yaoi, K.,Kondo, H.,Noro, N.,Suzuki, M.,Tsuda, S.,Mitsuishi, Y. (deposition date: 2004-03-19, release date: 2004-07-20, Last modification date: 2024-10-16)

Primary citation

Yaoi, K.,Kondo, H.,Noro, N.,Suzuki, M.,Tsuda, S.,Mitsuishi, Y.
Tandem Repeat of a Seven-Bladed beta-Propeller Domain in Oligoxyloglucan Reducing-End-Specific Cellobiohydrolase
Structure, 12:1209-1217, 2004

PubMed Abstract: Oligoxyloglucan reducing-end-specific cellobiohydrolase (OXG-RCBH; EC 3.2.1.150) is an exoglucanase that recognizes the reducing end of oligoxyloglucan and releases two glucosyl residue segments from the main chain. The X-ray crystal structure of OXG-RCBH determined at 2.2 A resolution reveals a unique feature of this enzyme; OXG-RCBH consists of a tandem repeat of two similar domains, which are both folded into seven-bladed beta-propeller structures. The sequence alignment of the propeller blades, based on the structure, indicates that a weak repeat of the amino acid sequence occurred seven times to construct each domain. There is a cleft that can accommodate the substrate oligosaccharide between the two domains, which is a putative substrate binding subsite. Mutation of either Asp35 or Asp465, located in the putative catalytic center, to Asn resulted in a protein with no detectable catalytic activity, indicating the critical role of these amino acids in catalysis.

PubMed: 15242597
DOI: 10.1016/j.str.2004.04.020

Experimental method

X-RAY DIFFRACTION (2.2 Å)