1J9Y

Crystal structure of mannanase 26A from Pseudomonas cellulosa

Summary for 1J9Y

• Entry DOI: 10.2210/pdb1j9y/pdb
• Descriptor: MANNANASE A, ZINC ION (3 entities in total)
• Functional Keywords: tim barrel, beta/alpha barrel, family 26 glycoside hydrolase, 4/7-superfamily of glycoside hydrolases, clan gh-a, hydrolase
• Biological source: Cellvibrio japonicus
• Total number of polymer chains: 1
• Total formula weight: 43878.08

Authors

Hogg, D.,Woo, E.-J.,Bolam, D.N.,McKie, V.A.,Gilbert, H.J.,Pickersgill, R.W. (deposition date: 2001-05-29, release date: 2001-06-20, Last modification date: 2024-02-07)

Primary citation

Hogg, D.,Woo, E.-J.,Bolam, D.N.,McKie, V.A.,Gilbert, H.J.,Pickersgill, R.W.
Crystal structure of mannanase 26A from Pseudomonas cellulosa and analysis of residues involved in substrate binding
J.Biol.Chem., 276:31186-31192, 2001

PubMed Abstract: The crystal structure of Pseudomonas cellulosa mannanase 26A has been solved by multiple isomorphous replacement and refined at 1.85 A resolution to an R-factor of 0.182 (R-free = 0.211). The enzyme comprises (beta/alpha)(8)-barrel architecture with two catalytic glutamates at the ends of beta-strands 4 and 7 in precisely the same location as the corresponding glutamates in other 4/7-superfamily glycoside hydrolase enzymes (clan GH-A glycoside hydrolases). The family 26 glycoside hydrolases are therefore members of clan GH-A. Functional analyses of mannanase 26A, informed by the crystal structure of the enzyme, provided important insights into the role of residues close to the catalytic glutamates. These data showed that Trp-360 played a critical role in binding substrate at the -1 subsite, whereas Tyr-285 was important to the function of the nucleophile catalyst. His-211 in mannanase 26A does not have the same function as the equivalent asparagine in the other GH-A enzymes. The data also suggest that Trp-217 and Trp-162 are important for the activity of mannanase 26A against mannooligosaccharides but are less important for activity against polysaccharides.

PubMed: 11382747
DOI: 10.1074/jbc.M010290200

Experimental method

X-RAY DIFFRACTION (1.85 Å)