Starch-binding domain

A) Circular amylose-GA-1 complex and (B) corresponding binding model the balls represent starch-binding domain (SBD) and the lines represent amylose chains (C) linear amylose-mutant GA-1 complex and (D) corresponding binding model. Image size ... 

Morris, V. J., Gunning, A. P., Faulds, C. B., Williamson, G., and Svensson, B. (2005). AFM images of complexes between amylose and Aspergillus niger glucoamylase mutants, native, and mutant starch binding domains A model for the action of glucoamylase. Starch-Starke 57,1-7. 

These transformations indicated that the starch binding domain of Rhizopus sp. glucoamylase was located at the N-terminus, and attached to the catalytic domain by a small linker domain (Figure 7.10). This is in contrast with the A. niger glucoamy-lases that have an opposite structure, with the catalytic domain at the N-terminus and the starch binding domain at the C-terminus. 

As discussed above, glucoamylases consist of three domains a catalytic domain a linker domain and a starch-binding domain. These domains can be in different orders in which the catalytic domain is located at the N-terminus or the C-terminus and conversely the starch-binding domain is at the C-terminus or the N-terminus, with the linker domain between the two. 

A few chimeric enzymes have been constructed by adding one or more domains from one amylolytic enzyme to another. Some of these chimeric enzymes have been studied in regard to the secretion of the enzyme,187 substrate specificity188 and product specificity.189 A starch binding domain from a Bacillus sp. cyclomaltodextrin glucanosyltransferase was fused with B. subtilis a-amylase, and an a-amylase was... 

The various soluble starch synthetases extend ot-(l->4)-glucans, starting from chain lengths of various sizes. SSI, for example, appears to have an extended starch-binding-domain at the C-terminus and transfer glucose residues up to a chain length of about 10. The three other soluble starch synthetases found in cereals (SSIIa, SSIIb and SSIII) appear to make longer chains between clusters there is a possibility that branches may have to be introduced before some of them operate. 

The function of CBM Family 20 (sometimes called SBD, starch binding domains) is particularly well understood in the case where it is attached to a GH 15 catalytic module, as in the Aspergillus spp. glucoamylase. The SBD contains two saccharide binding sites, each of which relies on a Trp residue to interact with the hydrophobic portion of the amylose unit. Mutation of either Trp residue gives an enzyme which continues to bind to soluble starch, but no... 

Matsui Y, Okada S, Uchimura T, Kondo A, Satoh E. (2007). Determination and analysis of the starch binding domain of Streptococcus bovis 148 raw-starch-hydrolyzing a-amylase. J Appl Glycosci, 54, 217-222. 

Juge, N., Nohr, J., Coeffet, M. F. L. G., Kramhoft, B., Fumiss, C. S. M., Planchot, V, Archer, D. B., Williamson, G., Svensson, B. The activity of barley a-amylase on starch granules is enhanced by fusion of a starch binding domain from Aspergillus niger glucoamy lase. Biocltem. Biophys. Acta. 2006, 8,275-284. 

Most fungal glucoamylases have a raw starch-binding domain (SBD) which is distinct from the catalytic domain. To obtain a better understanding of the role of this domain during the enzymatic process the inhibitors 43, 46, and 47 (Scheme 13) were used [40, 41],... 

Valdez, HA Busi, MV Wayllace, NZ Parisi, G Ugalde, RA Gomez-Casati, DF. Role of the N-terminal starch-binding domains in the kinetic properties of starch synthase III from Arabidopsis thaliana. Biochemistry, 2008, 47(9), 3026-32. 

Paldi, T Fevy, I Shoseyov, 0. Glucoamylase starch-binding domain of Aspergillus niger Bl molecular cloning and functional characterization. Biochem J., 2003, 372, 905-10. 

Ji, Q Oomen, RJFJ Vincken, J Bolam, DN Gilbert, HJ Suurs, FCJM et al. Reduction of starch granule size by expression of an engineered tandem starch-binding domain in potato plants. Plant Biotechnology Journal, 2004, 2(3), 251-60. 

Ji, Q Vincken, JP Suurs, EG Visser, RG. Microbial starch-binding domains as a tool for targeting proteins to granules during starch biosynthesis. Plant Mol Biol, 2003, 51(5), 789-801. 

Rodriguez-Sanoja, R Oviedo, N Sanchez, S. Microbial starch-binding domain. Curr OpinMicrobiol, 2005 Jun, 8(3), 260-7. 

Tarahomjoo, S Katakura, Y Shioya, S. New strategy for enhancement of microbial viability In simulated gastric conditions based on display of starch-binding domain on cell surface. JBiosci Bloeng, 2008 May, 105(5), 503-7. 

---