4bpx
From Proteopedia
Contents |
Crystal structure of human primase in complex with the primase- binding motif of DNA polymerase alpha
Template:ABSTRACT PUBMED 24043831
Function
[PRI1_HUMAN] DNA primase is the polymerase that synthesizes small RNA primers for the Okazaki fragments made during discontinuous DNA replication. [DPOLA_HUMAN] Plays an essential role in the initiation of DNA replication. During the S phase of the cell cycle, the DNA polymerase alpha complex (composed of a catalytic subunit POLA1/p180, a regulatory subunit POLA2/p70 and two primase subunits PRIM1/p49 and PRIM2/p58) is recruited to DNA at the replicative forks via direct interactions with MCM10 and WDHD1. The primase subunit of the polymerase alpha complex initiates DNA synthesis by oligomerising short RNA primers on both leading and lagging strands. These primers are initially extended by the polymerase alpha catalytic subunit and subsequently transferred to polymerase delta and polymerase epsilon for processive synthesis on the lagging and leading strand, respectively. The reason this transfer occurs is because the polymerase alpha has limited processivity and lacks intrinsic 3' exonuclease activity for proofreading error, and therefore is not well suited for replicating long complexes.[1]
About this Structure
4bpx is a 4 chain structure with sequence from Homo sapiens. Full crystallographic information is available from OCA.
Reference
- Kilkenny ML, Longo MA, Perera RL, Pellegrini L. Structures of human primase reveal design of nucleotide elongation site and mode of Pol alpha tethering. Proc Natl Acad Sci U S A. 2013 Sep 16. PMID:24043831 doi:10.1073/pnas.1311185110
