Synthesis of L-2,3-Diaminopropionic Acid, a Siderophore and Antibiotic Precursor

• Published in: Chemistry & biology Vol. 21; no. 3; pp. 379 - 388
• Main Authors: Kobylarz, Marek J., Grigg, Jason C., Takayama, Shin-ichi J., Rai, Dushyant K., Heinrichs, David E., Murphy, Michael E.P.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Ltd 20.03.2014
• Subjects: Anti-Bacterial Agents - chemistry; Bacterial Proteins - biosynthesis; Bacterial Proteins - chemistry; Bacterial Proteins - genetics; Bacterial Proteins - metabolism; beta-Alanine - analogs & derivatives; beta-Alanine - biosynthesis; beta-Alanine - chemistry; Binding Sites; Catalytic Domain; Citrates - biosynthesis; Citrates - chemistry; Crystallography, X-Ray; Glutamic Acid - analogs & derivatives; Glutamic Acid - metabolism; Hydrolysis; Ketoglutaric Acids - chemistry; Ketoglutaric Acids - metabolism; Molecular Dynamics Simulation; NAD - chemistry; NAD - metabolism; Phosphoserine - analogs & derivatives; Phosphoserine - metabolism; Recombinant Proteins - biosynthesis; Recombinant Proteins - chemistry; Recombinant Proteins - genetics; Siderophores - biosynthesis; Siderophores - chemistry; Staphylococcus aureus - enzymology; Staphylococcus aureus - metabolism
• ISSN: 1074-5521; 1879-1301
• DOI: 10.1016/j.chembiol.2013.12.011

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 α-ketoglutarate and L-Dap. Also, we describe crystal structures of SbnB in complex with NADH and ACEGA as well as with NAD+ and α-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. [Display omitted] •The product of SbnA is N-(1-amino-1-carboxyl-2-ethyl)-glutamic acid (ACEGA)•Hydrolysis of ACEGA by SbnB yields L-2,3-diaminopropionate and α-ketoglutarate•The substrates for SbnA are L-glutamate and O-phospho-L-serine•SbnA and SbnB contribute to the iron-sparing response of S. aureus L-2,3-diaminopropionic acid (L-Dap) is a biosynthetic precursor incorporated into both antibiotics and siderophores. Kobylarz et al. decipher the L-Dap biosynthetic pathway in Staphylococcus aureus that is essential for the assembly of the siderophore staphyloferrin B and contributes to the iron sparing response.