Matuschek M, Sahm K, Zibat A, Bahl H
Institut für Mikrobiologie, Georg-August-Universität Göttingen, Germany.
Mol Gen Genet. 1996 Sep 25;252(4):493-6. doi: 10.1007/BF02173016.
Two genes from Thermoanaerobacterium thermosulfurigenes EM1 were identified which are predicted to encode a xylanase (XynA) and a polygalacturonate hydrolase (Pg1A). The xynA gene has the potential to encode a 1234-amino acid product consisting of a signal peptide followed by a repeated domain, a xylanase family F domain, two cellulose-binding domains and a triplicated sequence at its C-terminus. The gene pglA is predicted to encode a product of 1148 amino acids consisting of a signal sequence followed by a fibronectin type III-like domain (Fn3 domain), the catalytic domain, a Gly/Thr/Ser/Asn-rich segment and a triplicated domain. The triplicated segments at the C-termini of deduced XynA and Pg1A are about 95% identical to each other and to the S-layer-like domains of the previously characterized pullulanase (AmyB) from the same organism. In contrast, sequence comparisons revealed only distant amino acid sequence similarities between the fibronectin type III-like domains of Pg1A and AmyB from T. thermosulfurigenes EM1.
已鉴定出来自嗜热栖热硫化叶菌EM1的两个基因，预计它们分别编码一种木聚糖酶（XynA）和一种聚半乳糖醛酸水解酶（Pg1A）。xynA基因有可能编码一个由1234个氨基酸组成的产物，该产物包含一个信号肽，其后依次是一个重复结构域、一个木聚糖酶家族F结构域、两个纤维素结合结构域以及在其C末端的一个三重重复序列。pglA基因预计编码一个由1148个氨基酸组成的产物，该产物包含一个信号序列，其后依次是一个纤连蛋白III型样结构域（Fn3结构域）、催化结构域、一个富含甘氨酸/苏氨酸/丝氨酸/天冬酰胺的片段以及一个三重重复结构域。推导出来的XynA和Pg1A在C末端的三重重复片段彼此之间以及与来自同一生物体的先前鉴定的支链淀粉酶（AmyB）的S层样结构域约95%相同。相比之下，序列比较显示嗜热栖热硫化叶菌EM1的Pg1A和AmyB的纤连蛋白III型样结构域之间只有远缘的氨基酸序列相似性。
