4EIP image
Deposition Date 2012-04-05
Release Date 2012-08-08
Last Version Date 2024-02-28
Entry Detail
PDB ID:
4EIP
Title:
Native and K252c bound RebC-10x
Biological Source:
Source Organism:
Host Organism:
Method Details:
Experimental Method:
Resolution:
2.33 Å
R-Value Free:
0.26
R-Value Work:
0.21
R-Value Observed:
0.21
Space Group:
P 1 21 1
Macromolecular Entities
Polymer Type:polypeptide(L)
Molecule:Putative FAD-monooxygenase
Gene (Uniprot):rbmD
Mutations:E36D, Q37A, T38A, R46K, G48S, Q117A, F216V, A231S, R239N, T241V
Chain IDs:A, B
Chain Length:549
Number of Molecules:2
Biological Source:Lechevalieria aerocolonigenes
Primary Citation
An Unusual Role for a Mobile Flavin in StaC-like Indolocarbazole Biosynthetic Enzymes.
Chem.Biol. 19 855 865 (2012)
PMID: 22840773 DOI: 10.1016/j.chembiol.2012.05.016

Abstact

The indolocarbazole biosynthetic enzymes StaC, InkE, RebC, and AtmC mediate the degree of oxidation of chromopyrrolic acid on route to the natural products staurosporine, K252a, rebeccamycin, and AT2433-A1, respectively. Here, we show that StaC and InkE, which mediate a net 4-electron oxidation, bind FAD with a micromolar K(d), whereas RebC and AtmC, which mediate a net 8-electron oxidation, bind FAD with a nanomolar K(d) while displaying the same FAD redox properties. We further create RebC-10x, a RebC protein with ten StaC-like amino acid substitutions outside of previously characterized FAD-binding motifs and the complementary StaC-10x. We find that these mutations mediate both FAD affinity and product specificity, with RebC-10x displaying higher StaC activity than StaC itself. X-ray structures of this StaC catalyst identify the substrate of StaC as 7-carboxy-K252c and suggest a unique mechanism for this FAD-dependent enzyme.

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Primary Citation of related structures