4MP6: Staphyloferrin B precursor biosynthetic enzyme SbnB bound to citrate and NAD+

L-2,3-diaminopropionic acid (L-Dap) is an amino acid that is a precursor of antibiotics and staphyloferrin B a siderophore produced by Staphylococcus aureus. SbnA and SbnB are encoded by the staphyloferrin B biosynthetic gene cluster and are implicated in L-Dap biosynthesis. We demonstrate here that SbnA uses PLP and substrates O-phospho-L-serine and L-glutamate to produce a metabolite N-(1-amino-1-carboxyl-2-ethyl)-glutamic acid (ACEGA). SbnB is shown to use NAD(+) to oxidatively hydrolyze ACEGA to yield alpha-ketoglutarate and L-Dap. Also, we describe crystal structures of SbnB in complex with NADH and ACEGA as well as with NAD(+) and alpha-ketoglutarate to reveal the residues required for substrate binding, oxidation, and hydrolysis. SbnA and SbnB contribute to the iron sparing response of S. aureus that enables staphyloferrin B biosynthesis in the absence of an active tricarboxylic acid cycle.
PDB ID: 4MP6Download
MMDB ID: 118036
PDB Deposition Date: 2013/9/12
Updated in MMDB: 2017/11
Experimental Method:
x-ray diffraction
Resolution: 2.1  Å
Source Organism:
Similar Structures:
Biological Unit for 4MP6: dimeric; determined by author and by software (PISA)
Molecular Components in 4MP6
Label Count Molecule
Proteins (2 molecules)
Putative Ornithine Cyclodeaminase
Molecule annotation
Chemicals (4 molecules)
* Click molecule labels to explore molecular sequence information.

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