PDBsum entry 3ept

Oxidoreductase

PDB id

3ept

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Contents

			Protein chains

					516 a.a. *

			Ligands

					FDA ×2

			Metals

					_NA

			Waters ×65

* Residue conservation analysis

PDB id:

3ept

Links

Name:

Oxidoreductase

Title:

Structure of the rebeccamycin biosynthetic enzyme rebc with reduced flavin

Structure:

Rebc. Chain: a, b. Synonym: putative monooxygenase, putative fad-monooxygenase. Engineered: yes

Source:

Lechevalieria aerocolonigenes. Organism_taxid: 68170. Gene: rbmd, rebc. Expressed in: escherichia coli. Expression_system_taxid: 562.

Resolution:

2.97Å

R-factor:

0.225

R-free:

0.276

Authors:

K.S.Ryan,C.L.Drennan

Key ref:

K.S.Ryan et al. (2008). The FAD cofactor of RebC shifts to an IN conformation upon flavin reduction. Biochemistry, 47, 13506-13513. PubMed id: 19035832

Date:

30-Sep-08

Release date:

09-Dec-08

PROCHECK

	Headers

	References

Protein chains

Q8KI25 (Q8KI25_LENAE) - Putative FAD-monooxygenase from Lentzea aerocolonigenes

Seq: Struc:

Seq: Struc:					529 a.a. 516 a.a.

Key:

PfamA domain

Secondary structure

CATH domain

	Biochemistry 47:13506-13513 (2008)
PubMed id: 19035832

The FAD cofactor of RebC shifts to an IN conformation upon flavin reduction.
K.S.Ryan, S.Chakraborty, A.R.Howard-Jones, C.T.Walsh, D.P.Ballou, C.L.Drennan.

ABSTRACT

RebC is a putative flavin hydroxylase functioning together with RebP to carry out a key step in the biosynthesis of rebeccamycin. To probe the mechanism of flavin-based chemistry in RebC, we solved the structure of RebC with reduced flavin. Upon flavin reduction, the RebC crystal undergoes a change in its unit cell dimension concurrent with a 5 A movement of the isoalloxazine ring, positioning the flavin ring adjacent to the substrate-binding pocket. Additionally, a disordered helix becomes ordered upon flavin reduction, closing off one side of the substrate-binding pocket. This structure, along with previously reported structures, increases our understanding of the RebC enzyme mechanism, indicating that either the reduction of the flavin itself or binding of substrate is sufficient to drive major conformational changes in RebC to generate a closed active site. Our finding that flavin reduction seals the active site such that substrate cannot enter suggests that our reduced flavin RebC structure is off-pathway and that substrate binding is likely to precede flavin reduction during catalysis. Along with kinetic data presented here, these structures suggest that the first cycle of catalysis in RebC may resemble that of p-hydroxybenzoate hydroxylase, with substrate binding promoting flavin reduction.

Literature references that cite this PDB file's key reference

PubMed id

Reference

21402075

G.Volkers, G.J.Palm, M.S.Weiss, G.D.Wright, and W.Hinrichs (2011).
Structural basis for a new tetracycline resistance mechanism relying on the TetX monooxygenase.

FEBS Lett, 585, 1061-1066.

PDB codes:

2xdo 2xyo 2y6q 2y6r

21290541

K.Groom, A.Bhattacharya, and D.L.Zechel (2011).
Rebeccamycin and staurosporine biosynthesis: insight into the mechanisms of the flavin-dependent monooxygenases RebC and StaC.

Chembiochem, 12, 396-400.

19364090

M.P.Beam, M.A.Bosserman, N.Noinaj, M.Wehenkel, and J.Rohr (2009).
Crystal structure of Baeyer-Villiger monooxygenase MtmOIV, the key enzyme of the mithramycin biosynthetic pathway .

Biochemistry, 48, 4476-4487.

PDB code:

3fmw

The most recent references are shown first. Citation data come partly from CiteXplore and partly from an automated harvesting procedure. Note that this is likely to be only a partial list as not all journals are covered by either method. However, we are continually building up the citation data so more and more references will be included with time. Where a reference describes a PDB structure, the PDB codes are shown on the right.