This old version of Proteopedia is provided for student assignments while the new version is undergoing repairs. Content and edits done in this old version of Proteopedia after March 1, 2026 will eventually be lost when it is retired in about June of 2026.
Apply for new accounts at the new Proteopedia. Your logins will work in both the old and new versions.
2hnf
From Proteopedia
| |||||||
| , resolution 1.80Å | |||||||
|---|---|---|---|---|---|---|---|
| Ligands: | |||||||
| Related: | 1F39, 1JHC, 1JHE, 2HO0
| ||||||
| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
Structure of a Hyper-cleavable Monomeric Fragment of Phage lambda Repressor Containing the Cleavage Site Region
Overview
The key event in the switch from lysogenic to lytic growth of phage lambda is the self-cleavage of lambda repressor, which is induced by the formation of a RecA-ssDNA-ATP filament at a site of DNA damage. Lambda repressor cleaves itself at the peptide bond between Ala111 and Gly112, but only when bound as a monomer to the RecA-ssDNA-ATP filament. Here we have designed a hyper-cleavable fragment of lambda repressor containing the hinge and C-terminal domain (residues 101-229), in which the monomer-monomer interface is disrupted by two point mutations and a deletion of seven residues at the C terminus. This fragment crystallizes as a monomer and its structure has been determined to 1.8 A resolution. The hinge region, which bears the cleavage site, is folded over the active site of the C-terminal oligomerization domain (CTD) but with the cleavage site flipped out and exposed to solvent. Thus, the structure represents a non-cleavable conformation of the repressor, but one that is poised for cleavage after modest rearrangements that are presumably stabilized by binding to RecA. The structure provides a unique snapshot of lambda repressor in a conformation that sheds light on how its self-cleavage is tempered in the absence of RecA, as well as a framework for interpreting previous genetic and biochemical data concerning the RecA-mediated cleavage reaction.
About this Structure
2HNF is a Single protein structure of sequence from Escherichia coli. Full crystallographic information is available from OCA.
Reference
Structure of a hyper-cleavable monomeric fragment of phage lambda repressor containing the cleavage site region., Ndjonka D, Bell CE, J Mol Biol. 2006 Sep 22;362(3):479-89. Epub 2006 Jul 15. PMID:16934834
Page seeded by OCA on Mon Mar 31 03:32:42 2008
