Download MendeleyCrystal Structures of the Iron-Sulfur Cluster-Dependent Quinolinate Synthase in Complex with Dihydroxyacetone Phosphate, Iminoaspartate Analogues, and Quinolinate.
Fenwick, M.K., Ealick, S.E.(2016) Biochemistry 55: 4135-4139
- PubMed: 27404889
- DOI: https://doi.org/10.1021/acs.biochem.6b00626
- Primary Citation of Related Structures:
5KTM, 5KTN, 5KTO, 5KTP, 5KTR, 5KTS, 5KTT - PubMed Abstract:
The quinolinate synthase of prokaryotes and photosynthetic eukaryotes, NadA, contains a [4Fe-4S] cluster with unknown function. We report crystal structures of Pyrococcus horikoshii NadA in complex with dihydroxyacetone phosphate (DHAP), iminoaspartate analogues, and quinolinate. DHAP adopts a nearly planar conformation and chelates the [4Fe-4S] cluster via its keto and hydroxyl groups. The active site architecture suggests that the cluster acts as a Lewis acid in enediolate formation, like zinc in class II aldolases. The DHAP and putative iminoaspartate structures suggest a model for a condensed intermediate. The ensemble of structures suggests a two-state system, which may be exploited in early steps.
Organizational Affiliation:
Department of Chemistry and Chemical Biology, Cornell University , Ithaca, New York 14853, United States.
