Kabiraj Ashutosh, Laha Anubhab, Panja Anindya Sundar, Bandopadhyay Rajib
Department of Botany, UGC-Centre for Advanced Study, The University of Burdwan, Golapbag, Bardhaman, West Bengal, 713104, India.
Department of Botany, Chandernagore College, Hooghly, Chandernagore, West Bengal, 712136, India.
J Genet Eng Biotechnol. 2023 May 19;21(1):64. doi: 10.1186/s43141-023-00522-9.
Arsenic, a ubiquitous toxic metalloid, is a threat to the survival of all living organisms. Bioaccumulation of arsenic interferes with the normal physiological pathway. To overcome arsenic toxicity, organisms have developed arsenite methyltransferase enzyme, which methylates inorganic arsenite to organic arsenic MMA (III) in the presence of S-adenosylmethionine (SAM). Bacteria-derived arsM might be horizontally transported to different domains of life as arsM or as3mt (animal ortholog). A systematic study on the functional diversity of arsenite methyltransferase from various sources will be used in arsenic bioremediation.
Several arsenite methyltransferase protein sequences of bacteria, fungi, fishes, birds, and mammals were retrieved from the UniProt database. In silico physicochemical studies confirmed the acidic, hydrophilic, and thermostable nature of these enzymes. Interkingdom relationships were revealed by performing phylogenetic analysis. Homology modeling was performed by SWISS-MODEL, and that was validated through SAVES-v.6.0. QMEAN values ranged from - 0.93 to - 1.30, ERRAT score (83-96), PROCHECK (88-92%), and other parameters suggested models are statistically significant. MOTIF and PrankWeb discovered several functional motifs and active pockets within the proteins respectively. The STRING database showed protein-protein interaction networks.
All of our in silico studies confirmed the fact that arsenite methyltransferase is a cytosolic stable enzyme with conserved sequences over a wide range of organisms. Thus, because of its stable and ubiquitous nature, arsenite methyltransferase could be employed in arsenic bioremediation.
砷是一种普遍存在的有毒类金属，对所有生物的生存构成威胁。砷的生物累积会干扰正常的生理途径。为了克服砷的毒性，生物体已进化出亚砷酸盐甲基转移酶，该酶在S-腺苷甲硫氨酸（SAM）存在的情况下将无机亚砷酸盐甲基化为有机砷MMA（III）。细菌来源的arsM可能会作为arsM或as3mt（动物直系同源物）水平转移到不同的生命域。对来自各种来源的亚砷酸盐甲基转移酶的功能多样性进行系统研究将用于砷的生物修复。
从UniProt数据库中检索到了细菌、真菌、鱼类、鸟类和哺乳动物的几种亚砷酸盐甲基转移酶蛋白质序列。计算机模拟的物理化学研究证实了这些酶的酸性、亲水性和热稳定性。通过系统发育分析揭示了不同界之间的关系。使用SWISS-MODEL进行同源建模，并通过SAVES-v.6.0进行验证。QMEAN值范围为 -0.93至 -1.30，ERRAT分数（83 - 96），PROCHECK（88 - 92%）以及其他参数表明模型具有统计学意义。MOTIF和PrankWeb分别在蛋白质中发现了几个功能基序和活性口袋。STRING数据库显示了蛋白质-蛋白质相互作用网络。
我们所有的计算机模拟研究都证实了这样一个事实，即亚砷酸盐甲基转移酶是一种胞质稳定酶，在广泛的生物体中具有保守序列。因此，由于其稳定且普遍存在的性质，亚砷酸盐甲基转移酶可用于砷的生物修复。
