Sandbox Reserved 310: Difference between revisions
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==Domains== | ==Domains== | ||
[[Image:FADbonding.jpg|thumb|left|300px|Figure 1. The hydrogen bonds the FAD ligand forms with nearby amino acid residues.]] | [[Image:FADbonding.jpg|thumb|left|300px|Figure 1. The hydrogen bonds the FAD ligand forms with nearby amino acid residues.]] | ||
The BLUF domain is a <scene name='Sandbox_Reserved_310/ | The BLUF domain is a <scene name='Sandbox_Reserved_310/Decamer/1'>decamer</scene> with a molecular weight of approximately 160kDa<ref name="one" />. There are ten monomers observed in each asymmetric unit. The crystalline structure of the BLUF domain from the T110078 protein was solved by single isomorphous replacement (SIR) method using a mercury derivative. The double ringed decamer has a diameter of approximately 95Å, a thickness of 60Å and a central channel approximately 35Å in diameter<ref name="one" />. | ||
Each monomer is comprised of 5 β-strands and 4 α-helices in the order of β1α1β2β3α2β4β5α3α4. Specifically, the BLUF domain of the monomer contains β1α1β2β3α2β4β5, while the C-terminal domain contains α3α4<ref name="one" />. The C-terminal domain interacts with the end of the β-sheet of the neighbouring monomer. | Each monomer is comprised of 5 <scene name='Sandbox_Reserved_310/Monomer/3'>β-strands</scene> and 4<scene name='Sandbox_Reserved_310/Monomer/2'>α-helices</scene> in the order of β1α1β2β3α2β4β5α3α4. Specifically, the BLUF domain of the monomer contains β1α1β2β3α2β4β5, while the C-terminal domain contains α3α4<ref name="one" />. The C-terminal domain interacts with the end of the β-sheet of the neighbouring monomer. | ||
The isoalloxazine ring of FAD is located between α1 and α2 of the BLUF domain, between two highly conserved hydrophobic residues: Ile24 and Ile66<ref name="one" />. FAD forms hydrogen bonds with the following amino acid residues: Asn21, Asn32, Gln50, Arg65 and Asp69<ref name="one" />. More specifically, the side chain of Asn31 binds to O2 of FAD and Asn32 binds to N3 and O4 of FAD. The guanido group of Arg65 contributes to a network between FAD and the apo protein. The amide N of the Gln50 sidechain interacts with N5 and O4 of FAD through hydrogen bonding, while the amide O of the sidechain is closely linked with the hydroxyl oxygen of the highly conserved Tyr8 residue, forming a FAD-Gln50-Tyr8 network<ref name="one" />. This conserved Tyr8 residue is the only residue that has been shown to be essential for light reaction in the BLUF domain containing AppA and Slr1694 proteins<ref name ="seven">PMID: 17042486</ref>. | The isoalloxazine ring of FAD is located between <scene name='Sandbox_Reserved_310/Monomer/4'>α1 and α2</scene> of the BLUF domain, between two highly conserved hydrophobic residues: Ile24 and Ile66<ref name="one" />. FAD forms hydrogen bonds with the following amino acid residues: Asn21, Asn32, Gln50, Arg65 and Asp69 (Figure 1)<ref name="one" />. More specifically, the side chain of Asn31 binds to O2 of FAD and Asn32 binds to N3 and O4 of FAD. The guanido group of Arg65 contributes to a network between FAD and the apo protein. The amide N of the Gln50 sidechain interacts with N5 and O4 of FAD through hydrogen bonding, while the amide O of the sidechain is closely linked with the hydroxyl oxygen of the highly conserved Tyr8 residue, forming a FAD-Gln50-Tyr8 network<ref name="one" />. This conserved Tyr8 residue is the only residue that has been shown to be essential for light reaction in the BLUF domain containing AppA and Slr1694 proteins<ref name ="seven">PMID: 17042486</ref>. | ||
==Further Analyses== | ==Further Analyses== | ||