6DI6

Crystal structure of eukaryotic DNA primase large subunit iron-sulfur cluster domain

Summary for 6DI6

• Entry DOI: 10.2210/pdb6di6/pdb
• Related: 6DTV 6DTZ 6DU0 6ID2
• Descriptor: DNA primase large subunit, IRON/SULFUR CLUSTER, (4S)-2-METHYL-2,4-PENTANEDIOL, ... (4 entities in total)
• Functional Keywords: dna primase, p58, iron-sulfur cluster, replication, regulatory subunit
• Biological source: Saccharomyces cerevisiae JAY291 (Baker's yeast)
• Total number of polymer chains: 1
• Total formula weight: 23951.30

Authors

Salay, L.E.,Chazin, W.J. (deposition date: 2018-05-22, release date: 2018-12-12, Last modification date: 2023-10-11)

Primary citation

O'Brien, E.,Salay, L.E.,Epum, E.A.,Friedman, K.L.,Chazin, W.J.,Barton, J.K.
Yeast require redox switching in DNA primase.
Proc. Natl. Acad. Sci. U.S.A., 115:13186-13191, 2018

PubMed Abstract: Eukaryotic DNA primases contain a [4Fe4S] cluster in the C-terminal domain of the p58 subunit (p58C) that affects substrate affinity but is not required for catalysis. We show that, in yeast primase, the cluster serves as a DNA-mediated redox switch governing DNA binding, just as in human primase. Despite a different structural arrangement of tyrosines to facilitate electron transfer between the DNA substrate and [4Fe4S] cluster, in yeast, mutation of tyrosines Y395 and Y397 alters the same electron transfer chemistry and redox switch. Mutation of conserved tyrosine 395 diminishes the extent of p58C participation in normal redox-switching reactions, whereas mutation of conserved tyrosine 397 causes oxidative cluster degradation to the [3Fe4S] species during p58C redox signaling. Switching between oxidized and reduced states in the presence of the Y397 mutations thus puts primase [4Fe4S] cluster integrity and function at risk. Consistent with these observations, we find that yeast tolerate mutations to Y395 in p58C, but the single-residue mutation Y397L in p58C is lethal. Our data thus show that a constellation of tyrosines for protein-DNA electron transfer mediates the redox switch in eukaryotic primases and is required for primase function in vivo.

PubMed: 30541886
DOI: 10.1073/pnas.1810715115

Experimental method

X-RAY DIFFRACTION (1.39 Å)