DNA-directed RNA Polymerase II Subunit RPB1, Recombinant, Drosophila Melanogaster, aa1579-1881, His-

DNA-dependent RNA polymerase catalyzes the transcription of DNA into RNA using the four ribonucleoside triphosphates as substrates. Largest and catalytic component of RNA polymerase II which synthesizes mRNA precursors and many functional non-coding RNAs. Forms the polymerase active center together with the second largest subunit. Pol II is the central component of the basal RNA polymerase II transcription machinery. It is composed of mobile elements that move relative to each other. RPB1 is part of the core element with the central large cleft, the clamp element that moves to open and close the cleft and the jaws that are thought to grab the incoming DNA template. At the start of transcription, a single-stranded DNA template strand of the promoter is positioned within the central active site cleft of Pol II. A bridging helix emanates from RPB1 and crosses the cleft near the catalytic site and is thought to promote translocation of Pol II by acting as a ratchet that moves the RNA-DNA hybrid through the active site by switching from straight to bent conformations at each step of nucleotide addition. During transcription elongation, Pol II moves on the template as the transcript elongates. Elongation is influenced by the phosphorylation status of the C-terminal domain (CTD) of Pol II largest subunit (RPB1), which serves as a platform for assembly of factors that regulate transcription initiation, elongation, termination and mRNA processing. Source: Recombinant protein corresponding to aa1579-1881 from drosophila melanogaster DNA-directed RNA Polymerase II Subunit RPB1, fused to His-Tag at N-terminal, expressed in Yeast. Molecular Weight: ~33.6kD, AA Sequence: YSPTSPNYTASSPGGASPNYSPSSPNYSPTSPLYASPRYASTTPNFNPQSTGYSPSSSGYSPTSPVYSPTVQFQSSPSFAGSGSNIYSPGNAYSPSSSNYSPNSPSYSPTSPSYSPSSPSYSPTSPCYSPTSPSYSPTSPNYTPVTPSYSPTSPNYSASPQYSPASPAYSQTGVKYSPTSPTYSPPSPSYDGSPGSPQYTPGSPQYSPASPKYSPTSPLYSPSSPQHSPSNQYSPTGSTYSATSPRYSPNMSIYSPSSTKYSPTSPTYTPTARNYSPTSPMYSPTAPSHYSPTSPAYSPSSPT, Storage and Stability: May be stored at 4°C for short-term only. Aliquot to avoid repeated freezing and thawing. Store at -20°C. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap. Further dilutions can be made in assay buffer.