4zn3

Publication Abstract from PubMed

Spt5 (NusG in bacteria) is the only RNA polymerase-associated factor known to be conserved in all three domains of life. In archaea and eukaryotes, Spt5 associates with Spt4, an elongation factor that is absent in bacteria, to form a functional heterodimeric complex. Previous studies suggest that the Spt4:Spt5 complex interacts directly with DNA at the double-stranded DNA exit tunnel of RNA polymerase to regulate gene transcription. In this study, the DNA-binding ability of Spt4:Spt5 from the archaeon Methanocaldococcus jannaschii was confirmed via nuclear magnetic resonance chemical shift perturbation and fluorescence polarization assays. Crystallographic analysis of the full-length MjSpt4:Spt5 revealed two distinct conformations of the C-terminal KOW domain of Spt5. A similar alkaline region was found on the Spt4:Spt5 surface in both crystal forms, and identified as double-stranded DNA binding patch through mutagenesis-fluorescence polarization assays. Based on these structural and biochemical data, the Spt4:Spt5-DNA binding model was built for the first time.

Structural and biochemical insights into the DNA-binding mode of MjSpt4p:Spt5 complex at the exit tunnel of RNAPII.,Guo G, Gao Y, Zhu Z, Zhao D, Liu Z, Zhou H, Niu L, Teng M J Struct Biol. 2015 Dec;192(3):418-25. doi: 10.1016/j.jsb.2015.09.023. Epub 2015 , Oct 14. PMID:26433031^[2]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.