Linde Mona, Peterhoff David, Sterner Reinhard, Babinger Patrick
From the Institute of Biophysics and Physical Biochemistry, University of Regensburg, 93040 Regensburg, Germany.
From the Institute of Biophysics and Physical Biochemistry, University of Regensburg, 93040 Regensburg, Germany
J Biol Chem. 2016 Jul 8;291(28):14861-70. doi: 10.1074/jbc.M115.711994. Epub 2016 May 14.
In Archaea, ether lipids play an essential role as the main building blocks of the cellular membrane. Recently, ether lipids have also been discovered in the domain of Bacteria, and the key enzymes that catalyze their synthesis, glycerol-1-phosphate dehydrogenase and heptaprenylglyceryl phosphate synthase, have been described. In Bacillales, heptaprenylglyceryl phosphate does not become linked to a second polyprenyl moiety like ether lipids in Archaea but is dephosphorylated and acetylated. Here, we report on the enzymes that catalyze these reactions. We enriched the phosphatase activity from a B. subtilis cell extract and suppose that dephosphorylation is catalyzed by the phosphatase PhoB or by any other phosphatase in an unspecific manner. By screening a B. subtilis knock-out library for deficiency in acetylation, the yvoF gene product was identified to be the acetyltransferase. The acetyl-CoA-dependent enzyme YvoF is a close relative of maltose O-acetyltransferase (MAT). Its catalytic properties were analyzed and compared with MAT. YvoF and MAT partially overlap in substrate and product range in vitro, but MAT is not able to complement the yvoF knock-out in vivo.
在古菌中，醚脂作为细胞膜的主要组成部分发挥着至关重要的作用。最近，在细菌域中也发现了醚脂，并且已经描述了催化其合成的关键酶，即甘油-1-磷酸脱氢酶和庚基戊烯基甘油磷酸合酶。在芽孢杆菌目中，庚基戊烯基甘油磷酸不像古菌中的醚脂那样与第二个聚戊烯基部分相连，而是被去磷酸化和乙酰化。在这里，我们报道了催化这些反应的酶。我们从枯草芽孢杆菌细胞提取物中富集了磷酸酶活性，并推测去磷酸化是由磷酸酶PhoB或任何其他磷酸酶以非特异性方式催化的。通过筛选枯草芽孢杆菌基因敲除文库中乙酰化缺陷，确定yvoF基因产物为乙酰转移酶。依赖乙酰辅酶A的酶YvoF是麦芽糖O-乙酰转移酶（MAT）的近亲。分析了其催化特性并与MAT进行了比较。YvoF和MAT在体外底物和产物范围上部分重叠，但MAT在体内不能补充yvoF基因敲除。
