Structure
The structure at right can be organized into regions and domains. There are three main regions: N-terminal region, catalytic region, and C-terminal glucan binding region.[1] The domains are more complex. There are five total domains; however, only four are visible in this crystal structure. Each domain consists of an N-terminal and C-terminal portion of the polypeptide chain, except Domain C, which is located at the bottom of the enzyme.[1] Following the polypeptide chain from N-terminus to C-terminus would pass through the domains in the following order: V, IV, B, A, C, A, B, IV, V.[2] CAN I ADD THE IMAGE FROM LEEMHUIS COMPARISON? A high degree of structural similarity exists within the GH70 family enzymes.[2]
Catalytic Domain
Domain A is regarded as the catalytic domain.[1] Within it, exists a highly conserved , which includes two aspartic acid residues and a general acid/base glutamate.[1] A calcium ion is also bound to help stabilize the formation of the catalytic domain.[1]
Supersecondary Structure
This enzyme features two well-known motifs. Domain A consists of a TIM barrel.[1] It is composed of a ring of beta strands surrounded by a ring of alpha helices. Domain C contains a greek key motif, which is four antiparallel beta strands that form a sheet.[2]
Function
Disease
Relevance
Based on the enzyme's contributions to dental cavity formation, this enzyme and its genes are attractive targets for inhibition.
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 Ito K, Ito S, Shimamura T, Weyand S, Kawarasaki Y, Misaka T, Abe K, Kobayashi T, Cameron AD, Iwata S. Crystal Structure of Glucansucrase from the Dental Caries Pathogen Streptococcus mutans. J Mol Biol. 2011 Feb 25. PMID:21354427 doi:10.1016/j.jmb.2011.02.028
- ↑ 2.0 2.1 2.2 2.3 Leemhuis H, Pijning T, Dobruchowska JM, van Leeuwen SS, Kralj S, Dijkstra BW, Dijkhuizen L. Glucansucrases: three-dimensional structures, reactions, mechanism, alpha-glucan analysis and their implications in biotechnology and food applications. J Biotechnol. 2013 Jan 20;163(2):250-72. doi: 10.1016/j.jbiotec.2012.06.037. Epub, 2012 Jul 10. PMID:22796091 doi:http://dx.doi.org/10.1016/j.jbiotec.2012.06.037
