title: Comparative characterization of the Arabidopsis subfamily a1 beta-galactosidases.
abstract: The Arabidopsis genome contains 17 predicted beta-galactosidase genes, all of which belong to glycosyl hydrolase (GH) Family 35. These genes have been further grouped into seven subfamilies based on sequence similarity. The largest of these, subfamily a1, consists of six genes, Gal-1 (At3g13750), Gal-2 (At3g52840), Gal-3 (At4g36360), Gal-4 (At5g56870), Gal-5 (At1g45130), and Gal-12 (At4g26140), some of which were characterized in previous studies. We report here the purification and biochemical characterization of recombinant Gal-1, Gal-3, Gal-4 and Gal-12 from Pichiapastoris, completing the analysis of all six recombinant proteins, as well as the isolation and characterization of the native Gal-2 protein from Arabidopsis leaves. Comparison of the relative expression levels of the subfamily a1 beta-galactosidases at the mRNA and protein levels uncovered evidence of differential regulation, which may involve post-transcriptional and post-translational processes. In addition, this study provides further support for the proposed function of the subfamily a1 beta-galactosidases in cell wall modification based on analysis of the organ-specific expression and subcellular localization of Gal-1 and Gal-12. Our study suggests that, despite some differences in individual biochemical characteristics and expression patterns, each member of the family has the potential to contribute to the dynamics of the Arabidopsis plant cell wall.
authors.affiliation: Department of Biological Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061-0308, USA.
authors.forename: Dashzeveg
authors.initials: D
authors.lastname: Gantulga
authors.forename: Young Ock
authors.initials: YO
authors.lastname: Ahn
authors.forename: Changhe
authors.initials: C
authors.lastname: Zhou
authors.forename: Dorjsuren
authors.initials: D
authors.lastname: Battogtokh
authors.forename: David R
authors.initials: DR
authors.lastname: Bevan
authors.forename: Brenda S J
authors.initials: BS
authors.lastname: Winkel
authors.forename: Asim
authors.initials: A
authors.lastname: Esen
mesh_terms: D017360:Arabidopsis / Q000201:enzymology* / Q000235:genetics; D029681:Arabidopsis Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D002473:Cell Wall / Q000201:enzymology* / Q000235:genetics; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D018745:Genome, Plant; D005810:Multigene Family; D018514:Plant Structures; D012333:RNA, Messenger / Q000378:metabolism; D011994:Recombinant Proteins; D004718:Saccharomycetales; D001616:beta-Galactosidase / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*
chemical_list: D029681:Arabidopsis Proteins; D012333:RNA, Messenger; D011994:Recombinant Proteins; D001616:beta-Galactosidase