Sánchez-Puelles J M, García J L, López R, García E
Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas, Madrid, Spain.
Gene. 1987;61(1):13-9. doi: 10.1016/0378-1119(87)90360-x.
Plasmids containing modifications at the 3' end of the lytA gene encoding the pneumococcal amidase were constructed by DNA recombinant techniques. Several deleted and fused amidases were obtained. These modified amidases were capable of degrading cell walls containing choline residues in their teichoic acid components without need of conversion (i.e., change of the inactive E form of amidase to the active C form). The reintroduction of as few as the terminal 11 amino acid (aa) residues present in the wild-type (wt) amidase into the sequence of the most extensively deleted form of the autolysin obtained in this work (E-520) partially restored the need of conversion. Our results demonstrate the importance of the C terminus for the catalytic activation of the wt amidase.
通过DNA重组技术构建了在编码肺炎球菌酰胺酶的lytA基因3'端含有修饰的质粒。获得了几种缺失和融合的酰胺酶。这些修饰的酰胺酶能够降解其磷壁酸成分中含有胆碱残基的细胞壁，而无需转化（即将酰胺酶的无活性E形式转变为活性C形式）。将野生型（wt）酰胺酶中仅末端11个氨基酸（aa）残基重新引入到本研究中获得的自溶素最广泛缺失形式（E-520）的序列中，部分恢复了转化的需求。我们的结果证明了C末端对于wt酰胺酶催化激活的重要性。
