SNAP-annotated 5mC-DNA-protein interactions: PDB entry 7nx5

PDB-id

7nx5; DSSR-derived features in text and JSON formats; DNAproDB

Class

viral protein

Method

X-ray (2.5 Å)

Summary

Crystal structure of the epstein-barr virus protein zebra (bzlf1, zta) bound to a methylated DNA duplex

Reference

Bernaudat F, Gustems M, Gunther J, Oliva MF, Buschle A, Gobel C, Pagniez P, Lupo J, Signor L, Muller CW, Morand P, Sattler M, Hammerschmidt W, Petosa C (2022): "Structural basis of DNA methylation-dependent site selectivity of the Epstein-Barr virus lytic switch protein ZEBRA/Zta/BZLF1." Nucleic Acids Res., 50, 490-511. doi: 10.1093/nar/gkab1183.

Abstract

In infected cells, Epstein-Barr virus (EBV) alternates between latency and lytic replication. The viral bZIP transcription factor ZEBRA (Zta, BZLF1) regulates this cycle by binding to two classes of ZEBRA response elements (ZREs): CpG-free motifs resembling the consensus AP-1 site recognized by cellular bZIP proteins and CpG-containing motifs that are selectively bound by ZEBRA upon cytosine methylation. We report structural and mutational analysis of ZEBRA bound to a CpG-methylated ZRE (meZRE) from a viral lytic promoter. ZEBRA recognizes the CpG methylation marks through a ZEBRA-specific serine and a methylcytosine-arginine-guanine triad resembling that found in canonical methyl-CpG binding proteins. ZEBRA preferentially binds the meZRE over the AP-1 site but mutating the ZEBRA-specific serine to alanine inverts this selectivity and abrogates viral replication. Our findings elucidate a DNA methylation-dependent switch in ZEBRA's transactivation function that enables ZEBRA to bind AP-1 sites and promote viral latency early during infection and subsequently, under appropriate conditions, to trigger EBV lytic replication by binding meZREs.

• The contacts include paired nucleotides (mostly a G in Watson-Crick G-C pairing) and amino-acids within a 4.5-Å distance cutoff to base atoms of 5mC.
• The structure is oriented in the base reference frame of 5mC, allowing for easy comparison and direct superimposition between entries.
• The black sphere (•) denotes the 5-methyl carbon atom in 5mC.