1GXM

Family 10 polysaccharide lyase from Cellvibrio cellulosa

Summary for 1GXM

• Entry DOI: 10.2210/pdb1gxm/pdb
• Related: 1GXN 1GXO
• Descriptor: PECTATE LYASE, GLYCEROL (3 entities in total)
• Functional Keywords: lyase, pectate, elimination
• Biological source: CELLVIBRIO CELLULOSA
• Total number of polymer chains: 2
• Total formula weight: 73791.71

Authors

Charnock, S.J.,Brown, I.E.,Turkenburg, J.P.,Black, G.W.,Davies, G.J. (deposition date: 2002-04-08, release date: 2002-10-04, Last modification date: 2024-05-08)

Primary citation

Charnock, S.J.,Brown, I.E.,Turkenburg, J.P.,Black, G.W.,Davies, G.J.
Convergent Evolution Sheds Light on the Anti-Beta-Elimination Mechanism Common to Family 1 and 10 Polysaccharide Lyases
Proc.Natl.Acad.Sci.USA, 99:12067-, 2002

PubMed Abstract: Enzyme-catalyzed beta-elimination of sugar uronic acids, exemplified by the degradation of plant cell wall pectins, plays an important role in a wide spectrum of biological processes ranging from the recycling of plant biomass through to pathogen virulence. The three-dimensional crystal structure of the catalytic module of a "family PL-10" polysaccharide lyase, Pel10Acm from Cellvibrio japonicus, solved at a resolution of 1.3 A, reveals a new polysaccharide lyase fold and is the first example of a polygalacturonic acid lyase that does not exhibit the "parallel beta-helix" topology. The "Michaelis" complex of an inactive mutant in association with the substrate trigalacturonate/Ca2+ reveals the catalytic machinery harnessed by this polygalacturonate lyase, which displays a stunning resemblance, presumably through convergent evolution, to the tetragalacturonic acid complex observed for a structurally unrelated polygalacturonate lyase from family PL-1. Common coordination of the -1 and +1 subsite saccharide carboxylate groups by a protein-liganded Ca2+ ion, the positioning of an arginine catalytic base in close proximity to the alpha-carbon hydrogen and numerous other conserved enzyme-substrate interactions, considered in light of mutagenesis data for both families, suggest a generic polysaccharide anti-beta-elimination mechanism.

PubMed: 12221284
DOI: 10.1073/PNAS.182431199

Experimental method

X-RAY DIFFRACTION (1.32 Å)