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CRYSTAL STRUCTURE OF THE HISTONE FROM METHANOPYRUS KANDLERICRYSTAL STRUCTURE OF THE HISTONE FROM METHANOPYRUS KANDLERI
Structural highlights
Publication Abstract from PubMedEukaryotic histone proteins condense DNA into compact structures called nucleosomes. Nucleosomes were viewed as a distinguishing feature of eukaryotes prior to identification of histone orthologs in methanogens. Although evolutionarily distinct from methanogens, the methane-producing hyperthermophile Methanopyrus kandleri produces a novel, 154-residue histone (HMk). Amino acid sequence comparisons show that HMk differs from both methanogenic and eukaryotic histones, in that it contains two histone-fold ms within a single chain. The two HMk histone-fold ms, N and C terminal, are 28% identical in amino acid sequence to each other and approximately 21% identical in amino acid sequence to other histone proteins. Here we present the 1.37-A-resolution crystal structure of HMk and report that the HMk monomer structure is homologous to the eukaryotic histone heterodimers. In the crystal, HMk forms a dimer homologous to [H3-H4](2) in the eukaryotic nucleosome. Based on the spatial similarities to structural ms found in the eukaryotic nucleosome that are important for DNA-binding, we infer that the Methanopyrus histone binds DNA in a manner similar to the eukaryotic histone tetramer [H3-H4](2). An ancestral nuclear protein assembly: crystal structure of the Methanopyrus kandleri histone.,Fahrner RL, Cascio D, Lake JA, Slesarev A Protein Sci. 2001 Oct;10(10):2002-7. PMID:11567091[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences |
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