title: Structural insights into the role of Bacillus subtilis YwfH (BacG) in tetrahydrotyrosine synthesis.
abstract: The synthesis of the dipeptide antibiotic bacilysin involves the sequential action of multiple enzymes in the bac operon. YwfH (also referred to as BacG) catalyzes the stereoselective reduction of dihydro-hydroxyphenylpyruvate (H2HPP) to tetrahydro-hydroxyphenylpyruvate (H4HPP) in this biosynthetic pathway. YwfH is an NADPH-dependent reductase that facilitates the conjugate addition of a hydride at the C4 olefin terminus of H2HPP. Here, the structure of YwfH is described at three conformational steps: the apo form, an apo-like conformation and the NADPH complex. YwfH is structurally similar to other characterized short-chain dehydrogenase/reductases despite having marginal sequence similarity. The structures of YwfH in different conformational states provide a rationale for the ping-pong reaction mechanism. The identification and role of the residues in the catalytic tetrad (Lys113-Tyr117-Ser155-Asn158) in proton transfer were examined by mutational analysis. Together, the structures and biochemical features revealed synchronized conformational changes that facilitate cofactor specificity and catalysis of H4HPP formation en route to tetrahydrotyrosine synthesis.
authors.affiliation: Molecular Biophysics Unit, Indian Institute of Science, Bangalore, Karnataka 560 012, India.
authors.forename: Malligarjunan
authors.initials: M
authors.lastname: Rajavel
authors.forename: Kumar
authors.initials: K
authors.lastname: Perinbam
authors.forename: B
authors.initials: B
authors.lastname: Gopal
mesh_terms: D001059:Apoproteins / Q000737:chemistry / Q000235:genetics / Q000502:physiology; D001412:Bacillus subtilis / Q000201:enzymology*; D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics / Q000502:physiology; D020134:Catalytic Domain / Q000235:genetics; D018360:Crystallography, X-Ray; D064429:Fatty Acid Synthases / Q000737:chemistry / Q000235:genetics / Q000502:physiology; D009247:NADH, NADPH Oxidoreductases / Q000737:chemistry / Q000235:genetics / Q000502:physiology; D044925:Oxidoreductases Acting on CH-CH Group Donors / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D011485:Protein Binding / Q000235:genetics; D011487:Protein Conformation; D013379:Substrate Specificity / Q000235:genetics; D014443:Tyrosine / Q000031:analogs & derivatives / Q000096:biosynthesis* / Q000737:chemistry
chemical_list: D001059:Apoproteins; D001426:Bacterial Proteins; D014443:Tyrosine; D044925:Oxidoreductases Acting on CH-CH Group Donors; C036543:short chain trans-2-enoyl-CoA reductase; D009247:NADH, NADPH Oxidoreductases; D064429:Fatty Acid Synthases
keywords: bac operon; short-chain dehydrogenase/reductases; tetrahydro-hydroxyphenylpyruvate synthesis; tetrahydrotyrosine