Structural highlights
FunctionC4R4Y0_KOMPG DNA-dependent RNA polymerase catalyzes the transcription of DNA into RNA using the four ribonucleoside triphosphates as substrates.[RuleBase:RU004279] Publication Abstract from PubMedThe histone H3-H4 octasome is a nucleosome-like particle in which two DNA gyres are wrapped around each histone (H3-H4)(2) tetramer disk, forming a clamshell-like configuration. In the present study, we performed in vitro RNA polymerase II (RNAPII) transcription assays with the H3-H4 octasome and found that RNAPII transcribed the H3-H4 octasome more efficiently than the nucleosome. RNAPII paused at only one position, superhelical location (SHL(-4)) in the H3-H4 octasome, in contrast to pausing at the SHL(-5), SHL(-2), and SHL(-1) positions in the nucleosome. Cryo-EM analysis revealed that two (H3-H4)(2) tetramer disks are retained when the RNAPII paused at the SHL(-4) position of the H3-H4 octasome. However, when RNAPII reached the SHL(-0.5) position, five base pairs before the dyad position of the H3-H4 octasome, the proximal (H3-H4)(2) tetramer was disassembled, but the distal (H3-H4)(2) tetramer still remained on the DNA. Therefore, RNAPII efficiently transcribes the H3-H4 octasome by stepwise (H3-H4)(2) tetramer disassembly. Structural basis of RNA polymerase II transcription on the histone H3-H4 octasome.,Ho CH, Nozawa K, Nishimura M, Oi M, Kujirai T, Ogasawara M, Ehara H, Sekine SI, Takizawa Y, Kurumizaka H J Biol Chem. 2026 Mar 4;302(4):111340. doi: 10.1016/j.jbc.2026.111340. PMID:41791711[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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