TY - JOUR
T1 - Molecular cloning and 3D structure prediction of the first raw-starch-degrading glucoamylase without a separate starch-binding domain
AU - Hostinová, Eva
AU - Solovicová, Adriana
AU - Dvorský, Radovan
AU - Gašperík, Juraj
PY - 2003/3/15
Y1 - 2003/3/15
N2 - Raw-starch-degrading glucoamylases have been known as multidomain enzymes consisting of a catalytic domain connected to a starch-binding domain (SBD) by an O-glycosylated linker region. A molecular genetics approach has been chosen to find structural differences between two related glucoamylases, raw-starch-degrading Glm and nondegrading Glu, from the yeasts Saccharomycopsis fibuligera IFO 0111 and HUT 7212, respectively. We have found that Glm and Glu show a high primary (77%) and tertiary structure similarity. Glm, although possessing a good ability for raw starch degradation, did not show consensus amino acid residues to any SBD found in glucoamylases or other amylolytic enzymes. Raw starch binding and digestion by Glm must thus depend on the existence of a site(s) lying within the intact protein which lacks a separate SBD. The enzyme represents a structurally new type of raw-starch-degrading glucoamylase.
AB - Raw-starch-degrading glucoamylases have been known as multidomain enzymes consisting of a catalytic domain connected to a starch-binding domain (SBD) by an O-glycosylated linker region. A molecular genetics approach has been chosen to find structural differences between two related glucoamylases, raw-starch-degrading Glm and nondegrading Glu, from the yeasts Saccharomycopsis fibuligera IFO 0111 and HUT 7212, respectively. We have found that Glm and Glu show a high primary (77%) and tertiary structure similarity. Glm, although possessing a good ability for raw starch degradation, did not show consensus amino acid residues to any SBD found in glucoamylases or other amylolytic enzymes. Raw starch binding and digestion by Glm must thus depend on the existence of a site(s) lying within the intact protein which lacks a separate SBD. The enzyme represents a structurally new type of raw-starch-degrading glucoamylase.
KW - Glucoamylase
KW - Primary structure
KW - Raw starch
KW - Saccharomycopsis fibuligera
KW - Starch-binding domain
KW - Tertiary structure model
UR - http://www.scopus.com/inward/record.url?scp=0037443714&partnerID=8YFLogxK
U2 - 10.1016/S0003-9861(03)00003-1
DO - 10.1016/S0003-9861(03)00003-1
M3 - Article
C2 - 12623067
AN - SCOPUS:0037443714
SN - 0003-9861
VL - 411
SP - 189
EP - 195
JO - Archives of Biochemistry and Biophysics
JF - Archives of Biochemistry and Biophysics
IS - 2
ER -