1b67: Difference between revisions

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CRYSTAL STRUCTURE OF THE HISTONE HMFA FROM METHANOTHERMUS FERVIDUS

OverviewOverview

The hyperthermophilic archaeon Methanothermus fervidus contains two small basic proteins, HMfA (68 amino acid residues) and HMfB (69 residues) that share a common ancestry with the eukaryal nucleosome core histones H2A, H2B, H3, and H4. HMfA and HMfB have sequences that differ at 11 locations, they have different structural stabilities, and the complexes that they form with DNA have different electrophoretic mobilities. Here, crystal structures are documented for recombinant (r) HMfA at a resolution of 1.55 A refined to a crystallographic R-value of 19.8 % (tetragonal form) and at 1.48 A refined to a R-value of 18.8 % (orthorhombic form), and for rHMfB at 1.9 A refined to a R-value of 18.0 %. The rHMfA and rHMfB monomers have structures that are just histone folds in which a long central alpha-helix (alpha2; 29 residues) is separated from shorter N-terminal (alpha1; 11 residues) and C-terminal (alpha3; 10 residues) alpha-helices by two loops (L1 and L2; both 6 residues). Within L1 and L2, three adjacent residues are in extended (beta) conformation. rHMfA and rHMfB assemble into homodimers, with the alpha2 helices anti-parallel aligned and crossing at an angle of close to 35 degrees, and with hydrogen bonds formed between the extended, parallel regions of L1 and L2 resulting in short beta-ladders. Dimerization creates a novel N-terminal structure that contains four proline residues, two from each monomer. As prolines are present at these positions in all archaeal histone sequences, this proline-tetrad structure is likely to be a common feature of all archaeal histone dimers. Almost all residues that participate in monomer-monomer interactions are conserved in HMfA and HMfB, consistent with the ability of these monomers to form both homodimers and (HMfA+HMfB) heterodimers. Differences in side-chain interactions that result from non-conservative residue differences in HMfA and HMfB are identified, and the structure of a (rHMfA)(2)-DNA complex is presented based on the structures documented here and modeled by homology to histone-DNA interactions in the eukaryal nucleosome.

About this StructureAbout this Structure

1B67 is a Single protein structure of sequence from Methanothermus fervidus with as ligand. Full crystallographic information is available from OCA.

ReferenceReference

Crystal structures of recombinant histones HMfA and HMfB from the hyperthermophilic archaeon Methanothermus fervidus., Decanniere K, Babu AM, Sandman K, Reeve JN, Heinemann U, J Mol Biol. 2000 Oct 13;303(1):35-47. PMID:11021968

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-[[Image:1b67.gif|left|200px]]<br /><applet load="1b67" size="450" color="white" frame="true" align="right" spinBox="true"
+[[Image:1b67.gif|left|200px]]<br /><applet load="1b67" size="350" color="white" frame="true" align="right" spinBox="true"
 caption="1b67, resolution 1.48&Aring;" />
 '''CRYSTAL STRUCTURE OF THE HISTONE HMFA FROM METHANOTHERMUS FERVIDUS'''<br />
 ==Overview==
-The hyperthermophilic archaeon Methanothermus fervidus contains two small, basic proteins, HMfA (68 amino acid residues) and HMfB (69 residues) that, share a common ancestry with the eukaryal nucleosome core histones H2A, H2B, H3, and H4. HMfA and HMfB have sequences that differ at 11 locations, they have different structural stabilities, and the complexes that they, form with DNA have different electrophoretic mobilities. Here, crystal, structures are documented for recombinant (r) HMfA at a resolution of 1.55, A refined to a crystallographic R-value of 19.8 % (tetragonal form) and at, 1.48 A refined to a R-value of 18.8 % (orthorhombic form), and for rHMfB, at 1.9 A refined to a R-value of 18.0 %. The rHMfA and rHMfB monomers have, structures that are just histone folds in which a long central alpha-helix, (alpha2; 29 residues) is separated from shorter N-terminal (alpha1; 11, residues) and C-terminal (alpha3; 10 residues) alpha-helices by two loops, (L1 and L2; both 6 residues). Within L1 and L2, three adjacent residues, are in extended (beta) conformation. rHMfA and rHMfB assemble into, homodimers, with the alpha2 helices anti-parallel aligned and crossing at, an angle of close to 35 degrees, and with hydrogen bonds formed between, the extended, parallel regions of L1 and L2 resulting in short, beta-ladders. Dimerization creates a novel N-terminal structure that, contains four proline residues, two from each monomer. As prolines are, present at these positions in all archaeal histone sequences, this, proline-tetrad structure is likely to be a common feature of all archaeal, histone dimers. Almost all residues that participate in monomer-monomer, interactions are conserved in HMfA and HMfB, consistent with the ability, of these monomers to form both homodimers and (HMfA+HMfB) heterodimers., Differences in side-chain interactions that result from non-conservative, residue differences in HMfA and HMfB are identified, and the structure of, a (rHMfA)(2)-DNA complex is presented based on the structures documented, here and modeled by homology to histone-DNA interactions in the eukaryal, nucleosome.
+The hyperthermophilic archaeon Methanothermus fervidus contains two small basic proteins, HMfA (68 amino acid residues) and HMfB (69 residues) that share a common ancestry with the eukaryal nucleosome core histones H2A, H2B, H3, and H4. HMfA and HMfB have sequences that differ at 11 locations, they have different structural stabilities, and the complexes that they form with DNA have different electrophoretic mobilities. Here, crystal structures are documented for recombinant (r) HMfA at a resolution of 1.55 A refined to a crystallographic R-value of 19.8 % (tetragonal form) and at 1.48 A refined to a R-value of 18.8 % (orthorhombic form), and for rHMfB at 1.9 A refined to a R-value of 18.0 %. The rHMfA and rHMfB monomers have structures that are just histone folds in which a long central alpha-helix (alpha2; 29 residues) is separated from shorter N-terminal (alpha1; 11 residues) and C-terminal (alpha3; 10 residues) alpha-helices by two loops (L1 and L2; both 6 residues). Within L1 and L2, three adjacent residues are in extended (beta) conformation. rHMfA and rHMfB assemble into homodimers, with the alpha2 helices anti-parallel aligned and crossing at an angle of close to 35 degrees, and with hydrogen bonds formed between the extended, parallel regions of L1 and L2 resulting in short beta-ladders. Dimerization creates a novel N-terminal structure that contains four proline residues, two from each monomer. As prolines are present at these positions in all archaeal histone sequences, this proline-tetrad structure is likely to be a common feature of all archaeal histone dimers. Almost all residues that participate in monomer-monomer interactions are conserved in HMfA and HMfB, consistent with the ability of these monomers to form both homodimers and (HMfA+HMfB) heterodimers. Differences in side-chain interactions that result from non-conservative residue differences in HMfA and HMfB are identified, and the structure of a (rHMfA)(2)-DNA complex is presented based on the structures documented here and modeled by homology to histone-DNA interactions in the eukaryal nucleosome.
 ==About this Structure==
-B67 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Methanothermus_fervidus Methanothermus fervidus] with SO4 as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1B67 OCA].
+B67 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Methanothermus_fervidus Methanothermus fervidus] with <scene name='pdbligand=SO4:'>SO4</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1B67 OCA].
 ==Reference==
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 [[Category: Decanniere, K.]]
 [[Category: Heinemann, U.]]
-[[Category: Reeve, J.N.]]
+[[Category: Reeve, J N.]]
 [[Category: Sandman, K.]]
 [[Category: SO4]]
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 [[Category: hmf1]]
-''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Tue Nov 20 11:23:40 2007''
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 11:52:01 2008''