ERCC6

DNA excision repair protein ERCC-6 (also CS-B protein) is a protein that in humans is encoded by the ERCC6 gene. The ERCC6 gene is located on the long arm of chromosome 10 at position 11.23.

Having 1 or more copies of a mutated ERCC6 causes Cockayne syndrome, type II.

Function

DNA can be damaged by ultraviolet radiation, toxins, radioactive substances, and reactive biochemical intermediates like free radicals. The ERCC6 protein is involved in repairing the genome when specific genes undergoing transcription (dubbed active genes) are inoperative; as such, CSB serves as a transcription-coupled excision repair protein, being one of the fundamental enzymes in active gene repair.

Structure and Mechanism

CSB has been found to exhibit ATPase properties; there are contradictory publications regarding the effect of ATP concentration on CSB's activity. The most recent evidence suggests that ADP/AMP allosterically regulate CSB. As such, it has been speculated that CSB may promote protein complex formation at repair sites subject to the ATP to ADP charge ratio.