2018/08/11 by Norbert K. Tavares, Chelsey M. VanDrisse, Jorge C. Escalante‐Semerena
Agricultural and Biological Sciences · Biochemistry, Genetics and Molecular Biology · Medicine · #Cassava research and cyanide #Folate and B Vitamins Research #Porphyrin Metabolism and Disorders
paper · doi:10.1111/mmi.14100
openalex publication_date 2018/08/11 · openalex created_date 2018/08/22 · openalex updated_date 2026/07/30
Summary Several of the enzymes involved in the conversion of adenosylcobyric acid (AdoCby) to adenosylcobamide (AdoCba) are yet to be identified and characterized in some cobamide (Cba)‐producing prokaryotes. Using a bioinformatics approach, we identified the bluE gene (locus tag RSP0788) of Rhodobacter sphaeroides 2.4.1 as a putative functional homolog of the L‐threonine kinase enzyme (PduX, EC 2.7.1.177) of S. enterica . In AdoCba, ( R )‐1‐aminopropan‐2‐ol O ‐phosphate (AP‐P) links the nucleotide loop to the corrin ring; most known AdoCba producers derive AP‐P from L‐Thr‐ O ‐3‐phosphate (L‐Thr‐P). Here, we show that Rs BluE has L‐Thr‐independent ATPase activity in vivo and in vitro . We used 31 P‐NMR spectroscopy to show that Rs BluE generates L‐Thr‐P at the expense of ATP and is unable to use L‐Ser as a substrate. BluE from R. sphaeroides or Rhodobacter capsulatus restored AdoCba biosynthesis in S. enterica Ε pduX and R. sphaeroides Ε bluE mutant strains. R. sphaeroides Ε bluE strains exhibited a decreased pigment phenotype that was restored by complementation with BluE. Finally, phylogenetic analyses revealed that bluE was restricted to the genomes of a few Rhodobacterales that appear to have a preference for a specific form of Cba, namely Coᴽ ‐( ᴽ ‐5,6‐dimethylbenzimidazolyl‐ Coᵦ ‐adenosylcobamide (a.k.a. adenosylcobalamin, AdoCbl; coenzyme B 12 , CoB 12 ).