Alternative clamp loaders/unloaders

Elg1, an alternative subunit of the RFC clamp loader, preferentially interacts with SUMOylated PCNA.

Replication-factor C (RFC) is a protein complex that loads the processivity clamp PCNA onto DNA. Elg1 is a conserved protein with homology to the largest subunit of RFC, but its function remained enigmatic. Here, we show that yeast Elg1 interacts physically and genetically with PCNA, in a manner that depends on PCNA modification, and exhibits preferential affinity for SUMOylated PCNA. This inte...

The TCF C-clamp DNA binding domain expands the Wnt transcriptome via alternative target recognition

LEF/TCFs direct the final step in Wnt/β-catenin signalling by recruiting β-catenin to genes for activation of transcription. Ancient, non-vertebrate TCFs contain two DNA binding domains, a High Mobility Group box for recognition of the Wnt Response Element (WRE; 5'-CTTTGWWS-3') and the C-clamp domain for recognition of the GC-rich Helper motif (5'-RCCGCC-3'). Two vertebrate TCFs (TCF-1/TCF7 and...

How a DNA polymerase clamp loader opens a sliding clamp.

Processive chromosomal replication relies on sliding DNA clamps, which are loaded onto DNA by pentameric clamp loader complexes belonging to the AAA+ family of adenosine triphosphatases (ATPases). We present structures for the ATP-bound state of the clamp loader complex from bacteriophage T4, bound to an open clamp and primer-template DNA. The clamp loader traps a spiral conformation of the ope...

Tarsorrhaphy lid clamp.

Tarsorrhaphy is finding increasing indications because of the resultant improvement in comeal metabolic activity and also the protective cover given to the cornea. Different techniques' have been described for performing the tarsorrhaphy, but the basic principle remains the same. It is to produce adhesions between the 2 lid margins by creating a raw intermarginal strip on the 2 lids. Tarsorrhap...

A New Eyelid Clamp