title: Post-translational processing of modular xylanases from Streptomyces is dependent on the carbohydrate-binding module.
abstract: Xylanases are very often modular enzymes composed of one or more catalytic domains and carbohydrate-binding modules (CBMs) connected by a flexible linker region. Usually, when these proteins are processed they lose their carbohydrate-binding capacity. Here, the role of the linker regions and cellulose- or xylan-binding domains in the processing of Xys1L from Streptomyces halstedii JM8 and Xyl30L from Streptomyces avermitilis UAH30 was studied. Xys1 variants with different linker lengths were tested, these being unable to avoid protein processing. Moreover, several fusion proteins between the Xys1 and Xyl30 domains were obtained and their proteolytic stability was studied. We demonstrate that CBM processing takes place even in the complete absence of the linker sequence. We also show that the specific carbohydrate module determines this cleavage in the proteins studied.
authors.affiliation: Instituto de Microbiología Bioquímica/Departamento de Microbiología y Genética, CSIC/Universidad de Salamanca, Edificio Departamental, Campus Miguel de Unamuno, 37007, Salamanca, Spain. mardi@usal.es
authors.forename: Margarita
authors.initials: M
authors.lastname: Díaz
authors.forename: José M
authors.initials: JM
authors.lastname: Fernández-Ábalos
authors.forename: Juan
authors.initials: J
authors.lastname: Soliveri
authors.forename: José L
authors.initials: JL
authors.lastname: Copa-Patiño
authors.forename: Ramón I
authors.initials: RI
authors.lastname: Santamaría
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D020134:Catalytic Domain; D002482:Cellulose / Q000378:metabolism; D008969:Molecular Sequence Data; D011499:Protein Processing, Post-Translational; D017434:Protein Structure, Tertiary; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D013302:Streptomyces / Q000201:enzymology*; D014990:Xylans / Q000378:metabolism; D014995:Xylosidases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D011993:Recombinant Fusion Proteins; D014990:Xylans; D002482:Cellulose; D014995:Xylosidases; C107879:Xys1 protein, Streptomyces halstedii