The small hSpt4 subunit of the human transcription elongation factor DSIF is a Zn-finger protein with alpha/beta type topology.
The eukaryotic transcription elongation factor 5,6-dichloro-1-beta-d-ribofuranosylbenzimidazole (DRB) sensitivity inducing factor (DSIF), is involved in regulating the processivity of RNA polymerase II. DSIF plays also a role in transcriptional activation, and in concert with the negative elongation factor NELF causes promoter proximal pausing of RNA polymerase II. Furthermore, DSIF has also been implicated in regulating the transcription of the human immunodeficiency virus proviral DNA. Human DSIF is composed of the two subunits, hSpt4 (p14) and hSpt5 (p160), corresponding to the yeast homologs Spt4 and Spt5. Here we show the purification and characterization of the small subunit, hSpt4. We were able to purify the protein in a soluble form separately from the larger hSpt5 subunit. CD and NMR spectroscopy show that the purified protein hSpt4 exhibits an alpha/beta topology with a well defined tertiary structure. Furthermore metal analysis by ICP-OES indicates that the protein contains a functional 4-Cys Zn-finger.
Wenzel
Sabine
S
Universität Bayreuth, Lehrstuhl für Struktur und Chemie der Biopolymere & Research Center for Biomacromolecules, 95440 Bayreuth, Germany.
Schweimer
Kristian
K
Rösch
Paul
P
Wöhrl
Birgitta M
BM
D000595:Amino Acid Sequence; D002942:Circular Dichroism; D006801:Humans; D008969:Molecular Sequence Data; D019906:Nuclear Magnetic Resonance, Biomolecular; D009687:Nuclear Proteins / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification*; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification; D012097:Repressor Proteins / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification*; D014157:Transcription Factors / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification*; D035602:Transcriptional Elongation Factors / Q000737:chemistry / Q000302:isolation & purification; D015032:Zinc / Q000032:analysis / Q000378:metabolism; D016335:Zinc Fingers
D009687:Nuclear Proteins; D011993:Recombinant Fusion Proteins; D012097:Repressor Proteins; C481011:SUPT4H1 protein, human; C112224:SUPT5H protein, human; D014157:Transcription Factors; D035602:Transcriptional Elongation Factors; D015032:Zinc