1khm
From Proteopedia
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C-TERMINAL KH DOMAIN OF HNRNP K (KH3)
Overview
Among it's many reported functions, heterogeneous nuclear, ribonucleoprotein (hnRNP) K is a transcription factor for the c- myc gene, a proto-oncogene critical for the regulation of cell growth and, differentiation. We have determined the solution structure of the, Gly26-->Arg mutant of the C-terminal K-homology (KH) domain of hnRNP K by, NMR spectroscopy. This is the first structure investigation of hnRNP K., Backbone residual dipolar couplings, which provide information that is, fundamentally different from the standard NOE-derived distance restraints, were employed to improve structure quality. An independent assessment of, structure quality was achieved by comparing the backbone15N T1/T2ratios to, the calculated structures. The C-terminal KH module of hnRNP K (KH3) is, revealed to be a three-stranded beta-sheet stacked against three, alpha-helices, two of which are nearly parallel to the strands of the, beta-sheet. The Gly26-->Arg mutation abolishes single-stranded DNA binding, without altering the overall fold of the protein. This provides a clue to, possible nucleotide binding sites of KH3. It appears unlikely that the, solvent-exposed side of the beta-sheet will be the site of protein-nucleic, acid complex formation. This is in contrast to the earlier theme for, protein-RNA complexes incorporating proteins structurally similar to KH3., We propose that the surface of KH3 that interacts with nucleic acid is, comparable to the region of DNA interaction for the double-stranded, DNA-binding domain of bovine papillomavirus-1 E2 that has a, three-dimensional fold similar to that of KH3.
About this Structure
1KHM is a Single protein structure of sequence from Homo sapiens. Full crystallographic information is available from OCA.
Reference
High precision solution structure of the C-terminal KH domain of heterogeneous nuclear ribonucleoprotein K, a c-myc transcription factor., Baber JL, Libutti D, Levens D, Tjandra N, J Mol Biol. 1999 Jun 18;289(4):949-62. PMID:10369774
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