Crystal structure of sucrose phosphorylase from Bifidobacterium adolescentis

TY - JOUR

T1 - Crystal structure of sucrose phosphorylase from Bifidobacterium adolescentis

AU - Sprogøe, Desiree

AU - van den Broek, Lambertus A M

AU - Mirza, Osman

AU - Kastrup, Jette Sandholm Jensen

AU - Voragen, Alphons G J

AU - Gajhede, Michael

AU - Skov, Lars

PY - 2004/2/10

Y1 - 2004/2/10

N2 - Around 80 enzymes are implicated in the generic starch and sucrose pathways. One of these enzymes is sucrose phosphorylase, which reversibly catalyzes the conversion of sucrose and orthophosphate to d-Fructose and alpha-d-glucose 1-phosphate. Here, we present the crystal structure of sucrose phosphorylase from Bifidobacterium adolescentis (BiSP) refined at 1.77 A resolution. It represents the first 3D structure of a sucrose phosphorylase and is the first structure of a phosphate-dependent enzyme from the glycoside hydrolase family 13. The structure of BiSP is composed of the four domains A, B, B', and C. Domain A comprises the (beta/alpha)(8)-barrel common to family 13. The catalytic active-site residues (Asp192 and Glu232) are located at the tips of beta-sheets 4 and 5 in the (beta/alpha)(8)-barrel, as required for family 13 members. The topology of the B' domain disfavors oligosaccharide binding and reduces the size of the substrate access channel compared to other family 13 members, underlining the role of this domain in modulating the function of these enzymes. It is remarkable that the fold of the C domain is not observed in any other known hydrolases of family 13. BiSP was found as a homodimer in the crystal, and a dimer contact surface area of 960 A(2) per monomer was calculated. The majority of the interactions are confined to the two B domains, but interactions between the loop 8 regions of the two barrels are also observed. This results in a large cavity in the dimer, including the entrance to the two active sites.

AB - Around 80 enzymes are implicated in the generic starch and sucrose pathways. One of these enzymes is sucrose phosphorylase, which reversibly catalyzes the conversion of sucrose and orthophosphate to d-Fructose and alpha-d-glucose 1-phosphate. Here, we present the crystal structure of sucrose phosphorylase from Bifidobacterium adolescentis (BiSP) refined at 1.77 A resolution. It represents the first 3D structure of a sucrose phosphorylase and is the first structure of a phosphate-dependent enzyme from the glycoside hydrolase family 13. The structure of BiSP is composed of the four domains A, B, B', and C. Domain A comprises the (beta/alpha)(8)-barrel common to family 13. The catalytic active-site residues (Asp192 and Glu232) are located at the tips of beta-sheets 4 and 5 in the (beta/alpha)(8)-barrel, as required for family 13 members. The topology of the B' domain disfavors oligosaccharide binding and reduces the size of the substrate access channel compared to other family 13 members, underlining the role of this domain in modulating the function of these enzymes. It is remarkable that the fold of the C domain is not observed in any other known hydrolases of family 13. BiSP was found as a homodimer in the crystal, and a dimer contact surface area of 960 A(2) per monomer was calculated. The majority of the interactions are confined to the two B domains, but interactions between the loop 8 regions of the two barrels are also observed. This results in a large cavity in the dimer, including the entrance to the two active sites.

KW - Amino Acid Sequence

KW - Bifidobacterium

KW - Binding Sites

KW - Crystallization

KW - Crystallography, X-Ray

KW - Dimerization

KW - Glucosyltransferases

KW - Models, Molecular

KW - Molecular Sequence Data

KW - Protein Folding

KW - Protein Structure, Tertiary

KW - Sequence Alignment

KW - Sequence Homology, Amino Acid

KW - Substrate Specificity

U2 - 10.1021/bi0356395

DO - 10.1021/bi0356395

M3 - Journal article

C2 - 14756551

SN - 0006-2960

VL - 43

SP - 1156

EP - 1162

JO - Biochemistry

JF - Biochemistry

IS - 5

ER -