1OCQ

COMPLEX OF THE ENDOGLUCANASE CEL5A FROM BACILLUS AGARADHEARANS AT 1.08 ANGSTROM RESOLUTION with cellobio-derived isofagomine

Summary for 1OCQ

• Entry DOI: 10.2210/pdb1ocq/pdb
• Related: 1A3H 1E5J 1H11 1H2J 1H5V 1HF6 1QHZ 1QI0 1QI2 2A3H 3A3H 4A3H 5A3H 6A3H 7A3H 8A3H
• Descriptor: ENDOGLUCANASE 5A, 5-HYDROXYMETHYL-3,4-DIHYDROXYPIPERIDINE, beta-D-glucopyranose, ... (6 entities in total)
• Functional Keywords: cellulose degradation, hydrolase, glycosidase, endoglucanase
• Biological source: BACILLUS AGARADHAERENS
• Total number of polymer chains: 1
• Total formula weight: 34605.60

Authors

Varrot, A.,Macdonald, J.,Stick, R.V.,Withers, S.G.,Davies, G.J. (deposition date: 2003-02-09, release date: 2003-06-26, Last modification date: 2023-12-13)

Primary citation

Varrot, A.,Tarling, C.A.,Macdonald, J.M.,Stick, R.V.,Zechel, D.L.,Withers, S.G.,Davies, G.J.
Direct Observation of the Protonation State of an Imino Sugar Glycosidase Inhibitor Upon Binding
J.Am.Chem.Soc., 125:7496-, 2003

PubMed Abstract: Glycosidases are some of the most ubiquitous enzyme in nature. Their biological significance, coupled to their enormous catalytic prowess derived from tight binding of the transition state, is reflected in their importance as therapeutic targets. Many glycosidase inhibitors are known. Imino sugars are often potent inhibitors, yet many facets of their mode of action, such as their degree, if any, of transition-state "mimicry" and their protonation state when bound to the target glycosidase remain unclear. Atomic resolution analysis of the endoglucanase, Cel5A, in complex with a cellobio-derived isofagomine in conjunction with the pH dependence of Ki and kcat/KM reveals that this compound binds as a protonated sugar. Surprisingly, both the enzymatic nucleophile and the acid/base are unprotonated in the complex.

PubMed: 12812472
DOI: 10.1021/JA034917K

Experimental method

X-RAY DIFFRACTION (1.08 Å)