1lr1 | pdb_00001lr1
Solution Structure of the Oligomerization Domain of the Bacterial Chromatin-Structuring Protein H-NS
Structural highlights
Function[HNS_ECOLI] A DNA-binding protein implicated in transcriptional repression (silencing) as well as in bacterial chromosome organization. H-NS binds tightly to AT-rich dsDNA, increases its thermal stability and inhibits transcription. Also binds to ssDNA and RNA but with a much lower affinity. H-NS has possible histone-like function. May be a global transcriptional regulator through its ability to bind to curved DNA sequences, which are found in regions upstream of a certain subset of promoters. Plays a role in the thermal control of pili and adhesive curli fimbriae production, by inducing transcription of csgD. Represses the CRISPR-cas promoters, permits only weak transcription of the crRNA precursor; its role is antagonized by LeuO. Subject to transcriptional auto-repression. Binds preferentially to the upstream region of its own gene recognizing two segments of DNA on both sides of a bend centered around -150.[1] [2] [3] [4] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedH-NS plays a role in condensing DNA in the bacterial nucleoid. This 136 amino acid protein comprises two functional domains separated by a flexible linker. High order structures formed by the N-terminal oligomerization domain (residues 1-89) constitute the basis of a protein scaffold that binds DNA via the C-terminal domain. Deletion of residues 57-89 or 64-89 of the oligomerization domain precludes high order structure formation, yielding a discrete dimer. This dimerization event represents the initial event in the formation of high order structure. The dimers thus constitute the basic building block of the protein scaffold. The three-dimensional solution structure of one of these units (residues 1-57) has been determined. Activity of these structural units is demonstrated by a dominant negative effect on high order structure formation on addition to the full length protein. Truncated and site-directed mutant forms of the N-terminal domain of H-NS reveal how the dimeric unit self-associates in a head-to-tail manner and demonstrate the importance of secondary structure in this interaction to form high order structures. A model is presented for the structural basis for DNA packaging in bacterial cells. H-NS oligomerization domain structure reveals the mechanism for high order self-association of the intact protein.,Esposito D, Petrovic A, Harris R, Ono S, Eccleston JF, Mbabaali A, Haq I, Higgins CF, Hinton JC, Driscoll PC, Ladbury JE J Mol Biol. 2002 Dec 6;324(4):841-50. PMID:12460581[5] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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