کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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1937796 | 1050726 | 2007 | 7 صفحه PDF | دانلود رایگان |
Hyaluronate lyases from Streptococcus pneumoniae (SpnHL) and Streptococcus agalactiae (SagHL) are composed of four domains; N-terminal domain, spacer domain, α-domain and C-terminal domain, which are connected through peptide linkers. We have earlier shown that the recombinant α- and C-terminal domains of SpnHL/SagHL interact with each other even in absence of the linker and form a functional complex with enhanced enzymatic activity. Here, we looked into the role of ionic interactions in the enzyme stability and also the role of C-terminal domain and linker in the functional regulation. Domain swapping studies showed that the C-terminal domain does not bind directly to the substrate; instead the domain contributes to the interaction with the polymeric hyaluronan for catalysis. Furthermore, the substrate specificity exchanges with the size of catalytic cleft. The role of linker connecting α-domain to C-terminal domain was found to hold the C-terminal domain in a conformation suitable for achieving maximum activity.
Journal: Biochemical and Biophysical Research Communications - Volume 353, Issue 2, 9 February 2007, Pages 286–292