title: Amy63, a novel type of marine bacterial multifunctional enzyme possessing amylase, agarase and carrageenase activities.
abstract: A multifunctional enzyme is one that performs multiple physiological functions, thus benefiting the organism. Characterization of multifunctional enzymes is important for researchers to understand how organisms adapt to different environmental challenges. In the present study, we report the discovery of a novel multifunctional enzyme Amy63 produced by marine bacterium Vibrio alginolyticus 63. Remarkably, Amy63 possesses amylase, agarase and carrageenase activities. Amy63 is a substrate promiscuous α-amylase, with the substrate priority order of starch, carrageenan and agar. Amy63 maintains considerable amylase, carrageenase and agarase activities and stabilities at wide temperature and pH ranges, and optimum activities are detected at temperature of 60 °C and pH of 6.0, respectively. Moreover, the heteroexpression of Amy63 dramatically enhances the ability of E. coli to degrade starch, carrageenan and agar. Motif searching shows three continuous glycosyl hydrolase 70 (GH70) family homologs existed in Amy63 encoding sequence. Combining serial deletions and phylogenetic analysis of Amy63, the GH70 homologs are proposed as the determinants of enzyme promiscuity. Notably, such enzymes exist in all kingdoms of life, thus providing an expanded perspective on studies of multifunctional enzymes. To our knowledge, this is the first report of an amylase having additional agarase and carrageenase activities.
authors.affiliation: Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China.|University of Chinese Academy of Sciences, Beijing, 100049, China.|Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266071, China.
authors.forename: Ge
authors.initials: G
authors.lastname: Liu
authors.affiliation: Key Laboratory of Biobased Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, 266101, China.
authors.forename: Shimei
authors.initials: S
authors.lastname: Wu
authors.affiliation: Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China.|Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266071, China.
authors.forename: Weihua
authors.initials: W
authors.lastname: Jin
authors.affiliation: Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China.|Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266071, China.
authors.forename: Chaomin
authors.initials: C
authors.lastname: Sun
mesh_terms: D000362:Agar / Q000737:chemistry; D000595:Amino Acid Sequence; D000681:Amylases / Q000737:chemistry* / Q000502:physiology; D001426:Bacterial Proteins / Q000737:chemistry* / Q000502:physiology; D002351:Carrageenan / Q000737:chemistry; D016384:Consensus Sequence; D004926:Escherichia coli; D019143:Evolution, Molecular; D005936:Glucans / Q000737:chemistry; D006026:Glycoside Hydrolases / Q000737:chemistry* / Q000502:physiology; D006863:Hydrogen-Ion Concentration; D064251:Multifunctional Enzymes / Q000737:chemistry / Q000502:physiology; D010802:Phylogeny; D013213:Starch / Q000737:chemistry / Q000378:metabolism; D013379:Substrate Specificity; D044149:Vibrio alginolyticus / Q000201:enzymology*
chemical_list: D001426:Bacterial Proteins; D005936:Glucans; D064251:Multifunctional Enzymes; C031146:maltoheptaose; D002351:Carrageenan; D000362:Agar; D013213:Starch; D000681:Amylases; D006026:Glycoside Hydrolases; C019624:agarase