Crystal Structure of Polygalacturonase fromErwinia carotovorassp.carotovora

Richard Pickersgill, Drummond Smith, Kathryn Worboys, John Jenkins
1998 Journal of Biological Chemistry  
The crystal structure of the 40-kDa endo-polygalacturonase from Erwinia carotovora ssp. carotovora was solved by multiple isomorphous replacement and refined at 1.9 Å to a conventional crystallographic R-factor of 0.198 and R free of 0.239. This is the first structure of a polygalacturonase and comprises a 10 turn righthanded parallel ␤-helix domain with two loop regions forming a "tunnel like" substrate-binding cleft. Sequence conservation indicates that the active site of polygalacturonase is
more » ... between these two loop regions, and comparison of the structure of polygalacturonase with that of rhamnogalacturonase A from Aspergillus aculeatus enables two conserved aspartates, presumed to be catalytic residues, to be identified. An adjacent histidine, in accord with biochemical results, is also seen. A similarity in overall electrostatic properties of the substrate-binding clefts of polygalacturonase and pectate lyase, which bind and cleave the same substrate, polygalacturonic acid, is also revealed.
doi:10.1074/jbc.273.38.24660 pmid:9733763 fatcat:qc4ochovkzdtnchvlkpcofmtqm