Mycobacterium tuberculosis ArfA Rv0899: Difference between revisions
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The C domain <scene name='61/612805/Secondary_structure_c/1'>residues 201-326</scene> The C domain of wild-type ArfA <scene name='61/612805/C_domain/3'></scene> <scene name='61/612805/C_domain_1/1'> folds </scene> into four {{Template:ColorKey_Strand}} and four {{Template:ColorKey_Helix}}.Three parallel (β1, β2, β3) and one antiparallel (β4) β-strands form a four-stranded β-sheet (β1–β4-β2–β3) that packs against three α-helices (α1, α2, α3), while a fourth helix (α4) extends from the N-terminus of β4. The structure <scene name='61/612805/C_domain_stabilization/2'> is stabilized </scene> by disulfide bond between C208 and C250, by a network of hydrophobic contacts between α1, α2 and β4 (L211, I215, V243, L247, Ile323 and V325) between side chains and by a hydrogen bond between the backbone amide of V325 and the side-chain carbonyl of Q212. | The C domain <scene name='61/612805/Secondary_structure_c/1'>residues 201-326</scene> The C domain of wild-type ArfA <scene name='61/612805/C_domain/3'></scene> <scene name='61/612805/C_domain_1/1'> folds </scene> into four {{Template:ColorKey_Strand}} and four {{Template:ColorKey_Helix}}.Three parallel (β1, β2, β3) and one antiparallel (β4) β-strands form a four-stranded β-sheet (β1–β4-β2–β3) that packs against three α-helices (α1, α2, α3), while a fourth helix (α4) extends from the N-terminus of β4. The structure <scene name='61/612805/C_domain_stabilization/2'> is stabilized </scene> by disulfide bond between C208 and C250, by a network of hydrophobic contacts between α1, α2 and β4 (L211, I215, V243, L247, Ile323 and V325) between side chains and by a hydrogen bond between the backbone amide of V325 and the side-chain carbonyl of Q212. | ||
== | ==Function== | ||
Stress response of the bacterium adaptation to the acidic environment. | |||
1.The B domain has homology with conserved putative <scene name='61/612805/Conserved_g95_and_g164_in_bon/2'>lipid-binding BON</scene> (bacterial OsmY and nodulation) superfamily domains and conserved Gly95 and Gly164 [http://www.ebi.ac.uk/interpro/entry/IPR014004]. Nitrogen fixation and / or nitrogen metabolism <ref>PMID: 12878000 </ref>. | 1.The B domain has homology with conserved putative <scene name='61/612805/Conserved_g95_and_g164_in_bon/2'>lipid-binding BON</scene> (bacterial OsmY and nodulation) superfamily domains and conserved Gly95 and Gly164 [http://www.ebi.ac.uk/interpro/entry/IPR014004]. Nitrogen fixation and / or nitrogen metabolism <ref>PMID: 12878000 </ref>. | ||
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3. Acquisition of Zn(2+) ions by {{Template:ColorKey Composition Ligand}} <scene name='61/612805/Binding-site_for_zn/1'>binding-site L82, D96, F97, H125, D127 and V129</scene> for DNA replication and transcription <ref>PMID: 22108166 </ref>. | 3. Acquisition of Zn(2+) ions by {{Template:ColorKey Composition Ligand}} <scene name='61/612805/Binding-site_for_zn/1'>binding-site L82, D96, F97, H125, D127 and V129</scene> for DNA replication and transcription <ref>PMID: 22108166 </ref>. | ||
a) deamidation of the amino acid pair <scene name='61/612805/Asn111_and_gly112/1'> Asn111-Gly112 </scene>, located at the end of α1 and preceding L3, a pH-dependent reaction whereby Asn is converted to Asp and ammonia is released. Asparagine residues preceding glycine, and situated in conformationally flexible regions of proteins, are frequently deamidated, with potentially significant consequences for protein regulation and function <ref>PMID: 20199110</ref>. [[Image:Asparaginase-reaction.jpg|250px]] | a) deamidation of the amino acid pair <scene name='61/612805/Asn111_and_gly112/1'> Asn111-Gly112 </scene>, located at the end of α1 and preceding L3, a pH-dependent reaction whereby Asn is converted to Asp and ammonia is released. Asparagine residues preceding glycine, and situated in conformationally flexible regions of proteins, are frequently deamidated, with potentially significant consequences for protein regulation and function <ref>PMID: 20199110</ref>. [[Image:Asparaginase-reaction.jpg|250px]] | ||