PDF
- Requires a PDF viewer such as GSview, Xpdf or Adobe Acrobat Reader
399kB |
Item Type: | Article |
---|---|
Title: | Auto-inhibitory effects of an IQ motif on protein structure and function |
Creators Name: | Petzhold, D., Lossie, J., Behlke, J., Keller, S., Haase, H. and Morano, I. |
Abstract: | The denuded IQ2 domain, i.e. myosin heavy chain not associated with regulatory light chains, exerts an inhibitory effect on myosin ATPase activity. In this study, we elaborated a structural explanation for this auto-inhibitory effect of IQ2 on myosin function. We employed analytical ultracentrifugation, circular dichroism, and surface plasmon resonance spectroscopy to investigate structural and functional properties of a myosin heavy chain (MYH) head-rod fragment aa664-915. MYH(664-915) was monomeric, adopted a closed shape, and bound essential myosin light chains (HIS-MLC-1) with low affinity to IQ1. Deletion of IQ2, however opened MYH(664-915). Four amino acids present in IQ2 could be identified to be responsible for this auto-inhibitory structural effect: alanine mutagenesis of I814, Q815, R819, and W827 stretched MYH(664-915) and increased 30fold the binding affinity of HIS-MLC-1 to IQ1. In this study we show, that denuded IQ2 favours a closed conformation of myosin with a low HIS-MLC-1 binding affinity. The collapsed structure of myosin with denuded IQ2 could explain the auto-inhibitory effects of IQ2 on enzymatic activity of myosin. |
Keywords: | IQ Motif, Myosin, Myosin Light Chains, Analytical Ultracentrifugation, Protein Structure, Protein–Protein-Interaction, Animals, Rats |
Source: | Biochemical and Biophysical Research Communications |
ISSN: | 0006-291X |
Publisher: | Academic Press |
Volume: | 396 |
Number: | 4 |
Page Range: | 939-943 |
Date: | 11 June 2010 |
Official Publication: | https://doi.org/10.1016/j.bbrc.2010.05.027 |
PubMed: | View item in PubMed |
Repository Staff Only: item control page