BMS 607 Lecture Notes - Lecture 14: Sp1 Transcription Factor, Histone H1, Puffy Amiyumi
Document Summary
Contains a lot of arginine and lysine. Histone octamer assembly: h3 and h4 form a dimer, then forms tetramer (h3-h4)2 they like to be symmetrical- h3/h4 and h4/h3, h2a and h2b form a dimer- do not form tetramer, but they alternate positions. Histones are synthesized during s phase; octamers are distributed during replication. Two pathways for new histone assembly: replication-coupled and replication-independent (transcription-coupled) Histone octamers are not conserved during replication: however, h2a/h2b dimers and (h3/h4)2 tetramers are conserved. Accessory proteins are required to assist the assembly of nucleosomes. Histones like to interact- form dimers, trimer, tetramer histone and replication: replication is organized temporally. Dna replication and dna methylation are both done semi- (cid:272)o(cid:374)ser(cid:448)ati(cid:448)el(cid:455): the pare(cid:374)t stra(cid:374)d templates the new area. Need to double number of histones and assemble the chromatin. Old (h2a- h(cid:1006)b(cid:895) (cid:272)a(cid:374) (cid:271)e i(cid:374)(cid:272)orporated (cid:449)ith old or (cid:374)e(cid:449) h(cid:1007)/h(cid:1008)