Chitinases are glycohydrolases that cleave β-1,4 linkages in chitin and are grouped into glycohydrolase (GH) family 18 and 19. GH18 chitinases are found ubiquitously, whereas GH19 chitinases are confined predominantly to higher plants and few bacteria. In this study, a new chitinolytic bacterium, Chitinophaga sp. YS-16, was isolated and identified as a close relative of Chitinophaga pinensis DSM 2588 with 99.41% similarity of 16S rRNA sequence. The gene encoding for GH19 chitinase bearing unique domain architecture was amplified from the genomic DNA of YS-16. The sequence of GH19 chitinase (CpChi) encoded in the genome of YS-16 showed 90.5% identity with the sequence of GH19 chitinase encoded in genome of C. pinensis DSM 2588 (ACU62980.1). Bioinformatics analyses of CpChi revealed it to be a ‘loopful’ chitinase which has been reported only from plants till date. The tertiary structure of the catalytic domain of CpChi (CtCpChi) was predicted by homology modelling. The docking of modelled structure of CtCpChi with oligomers of N-acetyl-d-glucosamine (GlcNAc) revealed that the binding cleft of CtCpChi could accommodate an octamer of GlcNAc, not known in any other reported bacterial chitinase. Phylogenetic analysis supports CtCpChi to be plant-like GH19 chitinase.

中文翻译：

---

来自新分离的 Chitinophaga sp. 的独特植物样“Loopful”GH19 几丁质酶的计算机表征。YS-16

几丁质酶是一种糖水解酶，可切割几丁质中的 β-1,4 键，并归入糖水解酶 (GH) 家族 18 和 19。GH18 几丁质酶无处不在，而 GH19 几丁质酶主要局限于高等植物和少数细菌。在这项研究中，一种新的几丁质分解细菌 Chitinophaga sp。YS-16，被分离并鉴定为Chitinophaga pinensis DSM 2588的近亲，与16S rRNA序列的相似性为99.41%。从 YS-16 的基因组 DNA 中扩增了编码具有独特结构域结构的 GH19 几丁质酶的基因。YS-16基因组中编码的GH19几丁质酶(CpChi)序列与C. pinensis DSM 2588 (ACU62980.1)基因组中编码的GH19几丁质酶序列具有90.5%的同一性。CpChi 的生物信息学分析表明它是一种“环状”几丁质酶，迄今为止仅在植物中报道过。CpChi (CtCpChi) 催化结构域的三级结构通过同源性建模预测。CtCpChi 的模型结构与 N-乙酰-d-葡糖胺 (GlcNAc) 的低聚物对接表明 CtCpChi 的结合裂缝可以容纳 GlcNAc 的八聚体，这在任何其他报道的细菌几丁质酶中都是未知的。系统发育分析支持 CtCpChi 是植物样 GH19 几丁质酶。在任何其他报道的细菌几丁质酶中未知。系统发育分析支持 CtCpChi 是植物样 GH19 几丁质酶。在任何其他报道的细菌几丁质酶中未知。系统发育分析支持 CtCpChi 是植物样 GH19 几丁质酶。