Purification and characterization of Hrp1, a Homolog of Mouse CHD1 from the fission yeast schizosaccharomyces pombe

Abstract

Hrp1, of Schizosaccharomyces pombe, is a new member of the SWI2/SNF2 protein family that contains a chromodomain and a DNA binding domain as well as ATPase/7 helicase domains. This configuration suggests that Hrp1 could be a homolog of mouse CHD1, which is thought to function in altering the chromatin structure to facilitate gene expression. To understand the enzymatic nature of Hrp1, we purified the 6‐Histidine‐tagged Hrp1 protein (6×His‐Hrp1) to homogeneity from a S. pombe Hrp1‐overexpressing strain and then examined its biochemical properties. We demonstrate that the purified 6×His‐Hrp1 protein exhibited a DNA‐binding activity with a moderate preference to the (A+T)‐rich tract in double‐stranded DNA via a minor groove interaction. However, we failed to detect any intrinsic DNA helicase activity from the purified Hrp1 like other SWI2/SNF2 proteins. These observations suggest that the DNA binding activities of Hrp1 may be involved in the remodeling of the chromatin structure with DNA‐dependent ATPase. We propose that Hrp1 may function in heterochromatins as other proteins with a chromo‐ or ATPase/helicase domain and play an important role in the determination of chromatin architecture

Key words:

• Hrp1
• CHD1 protein
• Schizosaccharomyces pombe

Notes

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