Polyhomeotic SAM domain structurePolyhomeotic SAM domain structure

Structural highlights

1kw4 is a 1 chain structure with sequence from Drosophila melanogaster. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:X-ray diffraction, Resolution 1.75Å
Ligands:
Resources:FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

PHP_DROME Polycomb group (PcG) protein. PcG proteins act by forming multiprotein complexes, which are required to maintain the transcriptionally repressive state of homeotic genes throughout development. PcG proteins are not required to initiate repression, but to maintain it during later stages of development. Component of the PcG multiprotein PRC1 complex, a complex that acts via chromatin remodeling and modification of histones; it mediates monoubiquitination of histone H2A 'Lys-118', rendering chromatin heritably changed in its expressibility. Plays a role in regulating the expression of other pair-rule genes such as eve, ftz, and H.[1]

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 PubMed

The polycomb group (PcG) proteins are important in the maintenance of stable repression patterns during development. Several PcG members contain a protein protein interaction module called a SAM domain (also known as SPM, PNT and HLH). Here we report the high-resolution structure of the SAM domain of polyhomeotic (Ph). Ph-SAM forms a helical polymer structure, providing a likely mechanism for the extension of PcG complexes. The structure of the polymer resembles that formed by the SAM domain of another transcriptional repressor, TEL. The formation of these polymer structures by SAM domains in two divergent repressors suggests a conserved mode of repression involving a higher order chromatin structure.

The SAM domain of polyhomeotic forms a helical polymer.,Kim CA, Gingery M, Pilpa RM, Bowie JU Nat Struct Biol. 2002 Jun;9(6):453-7. PMID:11992127[2]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

References

  1. DeCamillis M, Cheng NS, Pierre D, Brock HW. The polyhomeotic gene of Drosophila encodes a chromatin protein that shares polytene chromosome-binding sites with Polycomb. Genes Dev. 1992 Feb;6(2):223-32. PMID:1346609
  2. Kim CA, Gingery M, Pilpa RM, Bowie JU. The SAM domain of polyhomeotic forms a helical polymer. Nat Struct Biol. 2002 Jun;9(6):453-7. PMID:11992127 doi:http://dx.doi.org/10.1038/nsb802

1kw4, resolution 1.75Å

Drag the structure with the mouse to rotate

Proteopedia Page Contributors and Editors (what is this?)Proteopedia Page Contributors and Editors (what is this?)

OCA