Fleischman Nicholas M, Das Debanu, Kumar Abhinav, Xu Qingping, Chiu Hsiu-Ju, Jaroszewski Lukasz, Knuth Mark W, Klock Heath E, Miller Mitchell D, Elsliger Marc-André, Godzik Adam, Lesley Scott A, Deacon Ashley M, Wilson Ian A, Toney Michael D
Department of Chemistry, University of California, Davis, California, 95616.
Protein Sci. 2014 Aug;23(8):1060-76. doi: 10.1002/pro.2493. Epub 2014 Jun 14.
Pyridoxal-5'-phosphate or PLP, the active form of vitamin B6, is a highly versatile cofactor that participates in a large number of mechanistically diverse enzymatic reactions in basic metabolism. PLP-dependent enzymes account for ∼1.5% of most prokaryotic genomes and are estimated to be involved in ∼4% of all catalytic reactions, making this an important class of enzymes. Here, we structurally and functionally characterize three novel PLP-dependent enzymes from bacteria in the human microbiome: two are from Eubacterium rectale, a dominant, nonpathogenic, fecal, Gram-positive bacteria, and the third is from Porphyromonas gingivalis, which plays a major role in human periodontal disease. All adopt the Type I PLP-dependent enzyme fold and structure-guided biochemical analysis enabled functional assignments as tryptophan, aromatic, and probable phosphoserine aminotransferases.
磷酸吡哆醛（PLP）是维生素B6的活性形式，是一种用途广泛的辅因子，参与基础代谢中大量机制多样的酶促反应。依赖PLP的酶约占大多数原核生物基因组的1.5%，估计参与所有催化反应的约4%，使其成为一类重要的酶。在此，我们对来自人类微生物组中细菌的三种新型依赖PLP的酶进行了结构和功能表征：两种来自直肠真杆菌，这是一种占主导地位的、非致病性的、粪便中的革兰氏阳性菌，第三种来自牙龈卟啉单胞菌，它在人类牙周疾病中起主要作用。所有这些酶都采用I型依赖PLP的酶折叠方式，基于结构的生化分析确定它们的功能分别为色氨酸、芳香族和可能的磷酸丝氨酸转氨酶。
