InterPro domain: IPR013256

This entry includes the Saccharomyces cerevisiae (Baker's yeast) protein SPT2 which is a chromatin protein involved in transcriptional regulation [ 1 ].

These proteins shows conservation of several domains across numerous species, including having a cluster of positively charged amino acids. This cluster probably functions in the binding properties of the proteins [ 2 ]. Sin1p/Spt2p probably modulates the local chromatin structure by binding two strands of double-stranded DNA at their crossover point.

Sin1p/Spt2p has sequence similarity to HMG1 and serves as a negative transcriptional regulator of a small family of genes that are activated by the SWI/SNF chromatin-remodelling complex. It is also involved in maintaining the integrity of chromatin during transcription elongation. Sin1p/Spt2 is required for, and is directly involved in, the efficient recruitment of the mRNA cleavage/polyadenylation complex [ 2 ]. Spt2 is also involved in regulating levels of histone H3 over transcribed regions [ 3 ].

1. Functional domains of the yeast chromatin protein Sin1p/Spt2p can bind four-way junction and crossing DNA structures. J. Biol. Chem. 280, 5169-77
2. Recruitment of mRNA cleavage/polyadenylation machinery by the yeast chromatin protein Sin1p/Spt2p. Proc. Natl. Acad. Sci. U.S.A. 103, 9808-13
3. Evidence that Spt2/Sin1, an HMG-like factor, plays roles in transcription elongation, chromatin structure, and genome stability in Saccharomyces cerevisiae. Mol. Cell. Biol. 26, 1496-509