2iyg
From Proteopedia
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| - | [[Image:2iyg.gif|left|200px]]<br /> | + | [[Image:2iyg.gif|left|200px]]<br /><applet load="2iyg" size="450" color="white" frame="true" align="right" spinBox="true" |
| - | <applet load="2iyg" size="450" color="white" frame="true" align="right" spinBox="true" | + | |
caption="2iyg, resolution 2.30Å" /> | caption="2iyg, resolution 2.30Å" /> | ||
'''DARK STATE STRUCTURE OF THE BLUF DOMAIN OF THE RHODOBACTERIAL PROTEIN APPA'''<br /> | '''DARK STATE STRUCTURE OF THE BLUF DOMAIN OF THE RHODOBACTERIAL PROTEIN APPA'''<br /> | ||
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==About this Structure== | ==About this Structure== | ||
| - | 2IYG is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Rhodobacter_sphaeroides Rhodobacter sphaeroides] with FMN, DTU and DTT as [http://en.wikipedia.org/wiki/ligands ligands]. | + | 2IYG is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Rhodobacter_sphaeroides Rhodobacter sphaeroides] with FMN, DTU and DTT as [http://en.wikipedia.org/wiki/ligands ligands]. Known structural/functional Site: <scene name='pdbsite=AC1:Dtt Binding Site For Chain B'>AC1</scene>. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=2IYG OCA]. |
==Reference== | ==Reference== | ||
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[[Category: signal transduction]] | [[Category: signal transduction]] | ||
| - | ''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on | + | ''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Tue Dec 18 19:40:47 2007'' |
Revision as of 17:30, 18 December 2007
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DARK STATE STRUCTURE OF THE BLUF DOMAIN OF THE RHODOBACTERIAL PROTEIN APPA
Overview
Proteins containing a sensor of blue light using FAD (BLUF) domain control, diverse cellular processes, such as gene expression, nucleotide metabolism, and motility, by relaying blue light signals to distinct output units., Despite its crucial and widespread functions, the mechanism of BLUF signal, transduction has remained elusive. We determined crystal structures of the, dark-adapted state and of a photo-excited, red-shifted photocycle, intermediate of the BLUF unit of AppA, a purple bacterial photoreceptor, involved in the light-dependent regulation of photosynthesis gene, expression. In contrast to a recently published crystal structure of the, AppA BLUF domain determined in the presence of detergent molecules, our, structural model of the dark state corresponds well to those reported for, the BLUF domains of Tll0078 and BlrB. This establishes that a highly, conserved methionine (Met106 in AppA) is next to the active site glutamine, (Gln63 in AppA), which is of relevance for the latter's orientation in the, dark state and for the mechanism of the photoreaction. The comparison of, the dark-adapted and photointermediate state structures shows, light-induced conformational alterations, which suggest a path for signal, propagation. In particular, we observe a significant movement of the, Met106 side-chain. Met106 thereby changes its mode of interaction with, Gln63, which supports a light-dependent rotation of the latter. In view of, other BLUF structures available, our data further suggest that the, hydrogen bond between Asn45 and the backbone carbonyl of His105 breaks, upon illumination. The ensuing extensive structural rearrangement of, beta-strand 5 is predicted to involve a flip of Met106 out of the, flavin-binding pocket and Trp104 moving in to fill the void. We propose, that the blue light signal is transmitted towards the surface of the BLUF, domain via His44, which serves as a reporter of active site changes.
About this Structure
2IYG is a Single protein structure of sequence from Rhodobacter sphaeroides with FMN, DTU and DTT as ligands. Known structural/functional Site: . Full crystallographic information is available from OCA.
Reference
Crystal structures of the AppA BLUF domain photoreceptor provide insights into blue light-mediated signal transduction., Jung A, Reinstein J, Domratcheva T, Shoeman RL, Schlichting I, J Mol Biol. 2006 Sep 29;362(4):717-32. Epub 2006 Jul 15. PMID:16949615
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