Crystal structure of polygalacturonase from Erwinia carotovora ssp. carotovora.Pickersgill, R., Smith, D., Worboys, K., Jenkins, J.
(1998) J Biol Chem 273: 24660-24664
- PubMed: 9733763
- DOI: https://doi.org/10.1074/jbc.273.38.24660
- Primary Citation of Related Structures:
- PubMed Abstract:
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 A to a conventional crystallographic R-factor of 0.198 and Rfree of 0.239. This is the first structure of a polygalacturonase and comprises a 10 turn right-handed parallel beta-helix domain with two loop regions forming a "tunnel like" substrate-binding cleft. Sequence conservation indicates that the active site of polygalacturonase is 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.
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