2r57

From Proteopedia

Crystal Structure of the two MBT repeats from Sex-Comb on Midleg (SCM)

PDB ID 2r57

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Structural highlights

2r57 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 2.2Å
Resources:	FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

SCM_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. They probably act via the methylation of histones, rendering chromatin heritably changed in its expressibility.^[1] [UniProtKB:Q9W3C1]

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

Sex comb on midleg (Scm) is a member of the Polycomb group of proteins involved in the maintenance of repression of Hox and other developmental control genes in Drosophila. The two malignant brain tumour (MBT) repeats of Scm form a domain that preferentially binds to monomethylated lysine residues either as a free amino acid or in the context of peptides, while unmodified or di- or trimethylated lysine residues are bound with significantly lower affinity. The crystal structure of a monomethyl-lysine-containing histone tail peptide bound to the MBT repeat domain shows that the methyl-lysine side chain occupies a binding pocket in the second MBT repeat formed by three conserved aromatic residues and one aspartate. Insertion of the monomethylated side chain into this pocket seems to be the main contributor to the binding affinity. Functional analyses in Drosophila show that the MBT domain of Scm and its methyl-lysine-binding activity are required for repression of Hox genes.

Structural and functional analyses of methyl-lysine binding by the malignant brain tumour repeat protein Sex comb on midleg.,Grimm C, de Ayala Alonso AG, Rybin V, Steuerwald U, Ly-Hartig N, Fischle W, Muller J, Muller CW EMBO Rep. 2007 Nov;8(11):1031-7. Epub 2007 Oct 12. PMID:17932512^[2]

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

References

↑ Peterson AJ, Mallin DR, Francis NJ, Ketel CS, Stamm J, Voeller RK, Kingston RE, Simon JA. Requirement for sex comb on midleg protein interactions in Drosophila polycomb group repression. Genetics. 2004 Jul;167(3):1225-39. PMID:15280237 doi:http://dx.doi.org/10.1534/genetics.104.027474
↑ Grimm C, de Ayala Alonso AG, Rybin V, Steuerwald U, Ly-Hartig N, Fischle W, Muller J, Muller CW. Structural and functional analyses of methyl-lysine binding by the malignant brain tumour repeat protein Sex comb on midleg. EMBO Rep. 2007 Nov;8(11):1031-7. Epub 2007 Oct 12. PMID:17932512