Structure-based function prediction of the expanding mollusk tyrosinase family  

作　　者：黄荣莲 李莉 张国范 

机构地区：[1]Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences [2]University of Chinese Academy of Sciences [3]Marine Pearl Culture Lab, Fishery College, Guang Dong Ocean University [4]Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology

出　　处：《Chinese Journal of Oceanology and Limnology》2017年第6期1454-1464,共11页中国海洋湖沼学报（英文版）

基　　金：Supported by the National Natural Science Foundation of China(No.31530079);the Western Pacifi c Ocean System:Structure,Dynamics and Consequences(No.XDA11000000);the Technological Innovation Project(No.2015ASKJ02-03,fi nancially supported by Qingdao National Laboratory for Marine Science and Technology);the Earmarked Fund for Modern Agro-Industry Technology Research System(No.CARS-48)

摘　　要：Tyrosinase （Ty） is a common enzyme found in many different animal groups. In our previous study, genome sequencing revealed that the Ty family is expanded in the Pacific oyster （Crassostrea gigas）. Here, we examine the larger number of Ty family members in the Pacific oyster by high-level structure prediction to obtain more information about their function and evolution, especially the unknown role in biomineralization. We verified 12 Ty gene sequences from Crassostrea gigas genome and Pinctadafucata martensii transcriptome. By using phylogenetic analysis of these Tys with functionally known Tys from other molluscan species, eight subgroups were identified （CgTy_sl, CgTy s2, MolTy sl, MolTy-s2, MolTy-s3, PinTy-s 1, PinTy-s2 and PviTy）. Structural data and surface pockets of the dinuclear copper center in the eight subgroups of molluscan Ty were obtained using the latest versions of prediction online servers. Structural comparison with other Ty proteins from the protein databank revealed functionally important residues （HA1, HA2, HA3, HB1, HB2, HB3, Z l-Z9） and their location within these protein structures. The structural and chemical features of these pockets which may related to the substrate binding showed considerable variability among mollusks, which undoubtedly defines Ty substrate binding. Finally, we discuss the potential driving forces of Ty family evolution in mollusks. Based on these observations, we conclude that the Ty family has rapidly evolved as a consequence of substrate adaptation in mollusks.Tyrosinase(Ty) is a common enzyme found in many dif ferent animal groups. In our previous study, genome sequencing revealed that the Ty family is expanded in the Pacific oyster( Crassostrea gigas). Here, we examine the larger number of Ty family members in the Pacific oyster by high-level structure prediction to obtain more information about their function and evolution, especially the unknown role in biomineralization. We verified 12 Ty gene sequences from C rassostrea gigas genome and Pinctada fucata martensii transcriptome. By using phylogenetic analysis of these Tys with functionally known Tys from other molluscan species, eight subgroups were identified(Cg Ty_s1, Cg Ty_s2, Mol Ty_s1, Mol Ty-s2, Mol Ty-s3, Pin Ty-s1, Pin Ty-s2 and Pvi Ty). Structural data and surface pockets of the dinuclear copper center in the eight subgroups of molluscan Ty were obtained using the latest versions of prediction online servers. Structural comparison with other Ty proteins from the protein databank revealed functionally important residues(HA 1, H A2, H A3, H B1, H B2, H B3, Z1–Z9) and their location within these protein structures. The structural and chemical features of these pockets which may related to the substrate binding showed considerable variability among mollusks, which undoubtedly defines Ty substrate binding. Finally, we discuss the potential driving forces of Ty family evolution in mollusks. Based on these observations, we conclude that the Ty family has rapidly evolved as a consequence of substrate adaptation in mollusks.

关 键 词：TYROSINASE MOLLUSK ligand binding pocket substrate diversity evolution 

分 类 号：Q55[生物学—生物化学]