کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5532905 | 1402086 | 2016 | 16 صفحه PDF | دانلود رایگان |
- Comparison of crystal structures of PpSB1-LOV in dark and light states
- Dimer interface and the C-terminal Jα-helix show major structural rearrangements.
- A ~ 29° rotation between the two protein chains gated by light
- Extensive NMR solution studies reveal light-induced conformational changes.
- We propose a rotary switch mechanism for the activation.
Light-Oxygen-Voltage (LOV) domains represent the photo-responsive domains of various blue-light photoreceptor proteins and are widely distributed in plants, algae, fungi, and bacteria. Here, we report the dark-state crystal structure of PpSB1-LOV, a slow-reverting short LOV protein from Pseudomonas putida that is remarkably different from our previously published “fully light-adapted” structure [1]. A direct comparison of the two structures provides insight into the light-activated signaling mechanism. Major structural differences involve a ~ 11 à movement of the C terminus in helix Jα, ~ 4 à movement of Hβ-Iβ loop, disruption of hydrogen bonds in the dimer interface, and a ~ 29° rotation of chain-B relative to chain-A as compared to the light-state dimer. Both crystal structures and solution NMR data are suggestive of the key roles of a conserved glutamine Q116 and the N-cap region consisting of Aâ²Î±-Aβ loop and the Aâ²Î± helix in controlling the light-activated conformational changes. The activation mechanism proposed here for the PpSB1-LOV supports a rotary switch mechanism and provides insights into the signal propagation mechanism in naturally existing and artificial LOV-based, two-component systems and regulators.
Graphical Abstract133
Journal: Journal of Molecular Biology - Volume 428, Issue 19, 25 September 2016, Pages 3721-3736