Structure, Diversity, and Evolution of a New Family of Soluble Carotenoid-Binding Proteins in Cyanobacteria  

作　　者：Matthew R. Melnicki Ryan L. Leverenz Markus Sutter Rocio Lopez-lgual Adjele Wilson Emily G. Pawlowski Francois Perreau Diana Kirilovsky Cheryl A. Kerfeld 

机构地区：[1]Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720, USA [2]Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA [3]MSU-DOE Plant Research Laboratory, Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824, USA [4]Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Universite Paris-Sud, Universite Paris-Saclay, 91198 Gif-sur-Yvette, France [5]Commissariat & I'Energie Atomique (CEA), Institut de Biologie et Technologies de Saclay (iBiTec-S), 91191 Gif-sur-Yvette, France [6]INRA, Institut Jean-Pierre Bourgin, UMR 1318, ERL CNRS 3559, Saclay Plant Sciences, RD10, 78026 Versailles, France [7]Unite Plasticite du Genome Bacterien, Departement Genomes et Genetique, Institut Pasteur, CNRS, Unite Mixte de Recherche 3525, 75015 Paris, France

出　　处：《Molecular Plant》2016年第10期1379-1394,共16页分子植物（英文版）

基　　金：The work in the Kerfeld Laboratory was supported by the National Science Foundation （lOS 1557324） and by the Office of Science of the U.S. Depart- ment of Energy DE-FG02-91ER20021. The research in D.K.＇s laboratory was supported by grants from the Agence Nationale de la Recherche （ANR, project CYANOPROTECT）, the Centre National de la Recherche Scientifique （CNRS） and the Commissariat ＆ I＇Energie Atomique.ACKNOWLEDGMENTS We thank Prof. C. Peter Wolk （MSU-DOE Plant Research Laboratory and Department of Plant Biology, Michigan State University） for the gift of E, coil strain ED8654 and pRL443 plasmid. We are indebted to Dr. Enrique Ftores and Dr. Antonia Herrero （IBVF, Seville, Spain） for the Nostoc 7120 strain and the pRL277 plasmid. We thank Dr. Fei Cai for comments and assistance in revision of this manuscript. The Advanced Light Source is supported by the Director, Office of Science, Office of Basic Energy Sciences, of the U.S. Department of Energy under Contract No. DE-AC02- 05CH11231 No conflict of interest declared.

摘　　要：Using a phylogenomic approach, we have identified and subciassified a new family of carotenoid-binding proteins. These proteins have sequence homology to the N-terminal domain （NTD） of the Orange Carotenoid Protein （OCP）, and are referred to as Helical Carotenoid Proteins （HCPs）. These proteins comprise at least nine distinct ciades and are found in diverse organisms, frequently as multiple paralogs representing the distinct ciades. These seem to be out-paralogs maintained from ancient duplications associated with subfunctionalization. All of the HCPs share conservation of the residues for carotenoid binding, and we confirm that carotenoid binding is a fundamental property of HCPso We solved two crystal structures of the Nostoc sp. PCC 7120 HCP1 protein, each binding a different carotenoid, suggesting that the proteins flexibly bind a range of carotenoids. Based on a comprehensive phylogenetic analysis, we propose that one of the HCP subtypes is likely the evolutionary ancestor of the NTD of the OCP, which arose following a domain fusion evenS. However, we predict that the majority of HCPs have functions distinct from the NTD of the OCP. Our results demonstrate that the HCPs are a new family of functionally diverse carotenoid-binding proteins found among ecophysiologically diverse cyanobacteria.Using a phylogenomic approach, we have identified and subciassified a new family of carotenoid-binding proteins. These proteins have sequence homology to the N-terminal domain （NTD） of the Orange Carotenoid Protein （OCP）, and are referred to as Helical Carotenoid Proteins （HCPs）. These proteins comprise at least nine distinct ciades and are found in diverse organisms, frequently as multiple paralogs representing the distinct ciades. These seem to be out-paralogs maintained from ancient duplications associated with subfunctionalization. All of the HCPs share conservation of the residues for carotenoid binding, and we confirm that carotenoid binding is a fundamental property of HCPso We solved two crystal structures of the Nostoc sp. PCC 7120 HCP1 protein, each binding a different carotenoid, suggesting that the proteins flexibly bind a range of carotenoids. Based on a comprehensive phylogenetic analysis, we propose that one of the HCP subtypes is likely the evolutionary ancestor of the NTD of the OCP, which arose following a domain fusion evenS. However, we predict that the majority of HCPs have functions distinct from the NTD of the OCP. Our results demonstrate that the HCPs are a new family of functionally diverse carotenoid-binding proteins found among ecophysiologically diverse cyanobacteria.

关 键 词：carotenoids CYANOBACTERIA PHYLOGENOMICS protein structure PHOTOPROTECTION molecular evolution 

分 类 号：Q94[生物学—植物学]