Artículo
Starch synthesis in ostreococcus tauri: The starch-binding domains of starch synthase III-B are essential for catalytic activity
Barchiesi, Julieta
; Velázquez, María Belén
; Palopoli, Nicolás
; Iglesias, Alberto Alvaro
; Gomez Casati, Diego Fabian
; Ballicora, Miguel Angel; Busi, María Victoria
Fecha de publicación:
10/2018
Editorial:
Frontiers Research Foundation
Revista:
Frontiers in Plant Science
ISSN:
1664-462X
Idioma:
Inglés
Tipo de recurso:
Artículo publicado
Clasificación temática:
Resumen
Starch is the major energy storage carbohydrate in photosynthetic eukaryotes. Several enzymes are involved in building highly organized semi-crystalline starch granules, including starch-synthase III (SSIII), which is widely conserved in photosynthetic organisms. This enzyme catalyzes the extension of the α-1,4 glucan chain and plays a regulatory role in the synthesis of starch. Interestingly, unlike most plants, the unicellular green alga Ostreococcus tauri has three SSIII isoforms. In the present study, we describe the structure and function of OsttaSSIII-B, which has a similar modular organization to SSIII in higher plants, comprising three putative starch-binding domains (SBDs) at the N-terminal region and a C-terminal catalytic domain (CD). Purified recombinant OsttaSSIII-B displayed a high affinity toward branched polysaccharides such as glycogen and amylopectin, and to ADP-glucose. Lower catalytic activity was detected for the CD lacking the associated SBDs, suggesting that they are necessary for enzyme function. Moreover, analysis of enzyme kinetic and polysaccharide-binding parameters of site-directed mutants with modified conserved aromatic amino acid residues W122, Y124, F138, Y147, W279, and W304, belonging to the SBDs, revealed their importance for polysaccharide binding and SS activity. Our results suggest that OT_ostta13g01200 encodes a functional SSIII comprising three SBD domains that are critical for enzyme function.
Palabras clave:
ENZYME REGULATION
,
MICROALGAE
,
STARCH
,
STARCH SYNTHASE
,
STARCH-BINDING DOMAINS
Archivos asociados
Licencia
Identificadores
Colecciones
Articulos(CEFOBI)
Articulos de CENTRO DE EST.FOTOSINTETICOS Y BIOQUIMICOS (I)
Articulos de CENTRO DE EST.FOTOSINTETICOS Y BIOQUIMICOS (I)
Articulos(IAL)
Articulos de INSTITUTO DE AGROBIOTECNOLOGIA DEL LITORAL
Articulos de INSTITUTO DE AGROBIOTECNOLOGIA DEL LITORAL
Articulos(SEDE CENTRAL)
Articulos de SEDE CENTRAL
Articulos de SEDE CENTRAL
Citación
Barchiesi, Julieta; Velázquez, María Belén; Palopoli, Nicolás; Iglesias, Alberto Alvaro; Gomez Casati, Diego Fabian; et al.; Starch synthesis in ostreococcus tauri: The starch-binding domains of starch synthase III-B are essential for catalytic activity; Frontiers Research Foundation; Frontiers in Plant Science; 9; 10-2018; 1-11
Compartir
Altmétricas
Items relacionados
Mostrando titulos relacionados por título, autor y tema.
-
Teobaldi, Andrés Gustavo; Barrera, Gabriela ; Severini, Hernán Claudio; Ribotta, Pablo Daniel (John Wiley & Sons Ltd, 2022-09)
-
Schönhals, Elske Maria; Ding, Jia; Ritter, Enrique; Paulo, Maria João; Cara, Nicolás ; Tacke, Ekhard; Hofferbert, Hans-Reinhard; Lübeck, Jens; Strahwald, Josef; Gebhardt, Christiane (BioMed Central, 2017-08)
-
Barchiesi, Julieta ; Hedin, Nicolas ; Gomez Casati, Diego Fabian ; Ballicora, Miguel; Busi, María Victoria (BioMed Central, 2015-10)