Pascarella S, Schirch V, Bossa F
Dipartimento di Scienze Biochimiche A Rossi Fanelli, Università La Sapienza, Roma, Italy.
FEBS Lett. 1993 Sep 27;331(1-2):145-9. doi: 10.1016/0014-5793(93)80314-k.
A structural homology of the pyridoxal-5'-phosphate (PLP)-dependent enzyme serine hydroxymethyltransferase (SHMT) with aspartate aminotransferase (AAT) is proposed. Although the two sequences are very dissimilar, a reasonable alignment was obtained using the profile analysis method. Sequences of AAT and dialkylglycine decarboxylase (DGD), for which crystal structure data are available, have been aligned on the basis of their structure superposition. A profile was then calculated and SHMT sequence aligned to it. Three of the four residues conserved in all aminotransferases (including the PLP-binding lysine) are matched. A profile search with DGD-AAT-SHMT profile is more selective and sensitive than individual sequence profiles for PLP-dependent enzyme detection. Potential homologies with the eryC1 gene product involved in erythromycin biosynthesis and with amino acid decarboxylases were observed. Homology with AAT will be used as a guideline for planning site-directed mutagenesis experiments on SHMT.
有人提出吡哆醛 - 5'-磷酸（PLP）依赖性酶丝氨酸羟甲基转移酶（SHMT）与天冬氨酸氨基转移酶（AAT）存在结构同源性。尽管这两个序列差异很大，但使用轮廓分析方法获得了合理的比对结果。已根据其结构叠加对可获得晶体结构数据的AAT和二烷基甘氨酸脱羧酶（DGD）的序列进行了比对。然后计算了一个轮廓，并将SHMT序列与之比对。所有转氨酶中保守的四个残基中的三个（包括与PLP结合的赖氨酸）相匹配。使用DGD - AAT - SHMT轮廓进行的轮廓搜索比用于PLP依赖性酶检测的单个序列轮廓更具选择性和敏感性。观察到与参与红霉素生物合成的eryC1基因产物以及氨基酸脱羧酶存在潜在的同源性。与AAT的同源性将用作规划SHMT定点诱变实验的指导。
