title: Crystal structure and substrate-binding mode of a novel pectate lyase from alkaliphilic Bacillus sp. N16-5.
abstract: The pectate lyase (Bsp165PelA) from Bacillus sp. N16-5 has great potential in industrial applications because it shows high specific activity under extremely alkaline conditions. Besides, activity measurement of Bsp165PelA does not require addition of calcium, in a way different from the other pectate lyases. Here we report crystal structures of Bsp165PelA in apo-form and in complex with trigalacturonate. The parallel β-helix, active site residues and substrate binding cleft are similar to those in the other pectate lyases from Polysaccharide Lyase family 1. However, some of the highly conserved Ca(2+) binding residues and secondary structures are altered in Bsp165PelA, making it difficult to coordinate with Ca(2+) as in the other pectate lyases. We found Bsp165PelA forms some direct enzyme-substrate interactions instead of using Ca(2+) ions bridging in the extremely alkaline environment.
authors.affiliation: Industrial Enzymes National Engineering Laboratory, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China.
authors.forename: Yingying
authors.initials: Y
authors.lastname: Zheng
authors.forename: Chun-Hsiang
authors.initials: CH
authors.lastname: Huang
authors.forename: Wenting
authors.initials: W
authors.lastname: Liu
authors.forename: Tzu-Ping
authors.initials: TP
authors.lastname: Ko
authors.forename: Yanfen
authors.initials: Y
authors.lastname: Xue
authors.forename: Cheng
authors.initials: C
authors.lastname: Zhou
authors.forename: Rey-Ting
authors.initials: RT
authors.lastname: Guo
authors.forename: Yanhe
authors.initials: Y
authors.lastname: Ma
mesh_terms: D000595:Amino Acid Sequence; D001407:Bacillus / Q000201:enzymology*; D018360:Crystallography, X-Ray; D008969:Molecular Sequence Data; D011133:Polysaccharide-Lyases / Q000737:chemistry*; D011487:Protein Conformation; D013379:Substrate Specificity
chemical_list: D011133:Polysaccharide-Lyases; C023911:pectate lyase