27ZK
Atomic structure of the ASFV virus early transcription factor in ER state
Summary for 27ZK
| Entry DOI | 10.2210/pdb27zk/pdb |
| EMDB information | 81562 |
| Descriptor | Early transcription factor large subunit homolog (2 entities in total) |
| Functional Keywords | complex, transcription |
| Biological source | African swine fever virus BA71V More |
| Total number of polymer chains | 2 |
| Total formula weight | 289857.88 |
| Authors | |
| Primary citation | Yang, Y.,Xin, Y.,Liu, C.,Zhang, O.,Rao, Z.,Li, X.,Chen, Y. Structural insights into the early transcription factors of the African swine fever virus. Int.J.Biol.Macromol., 384:154747-154747, 2026 Cited by PubMed Abstract: African swine fever virus (ASFV) relies on a virus-encoded transcription machinery to initiate gene expression within cytoplasmic viral factories. The viral early transcription factor (VETF), a heterodimer composed of pD1133L and pG1340L, is required for early transcription and viral replication, yet its structural organization and regulation remain poorly understood. Here, we present cryo-EM structures of ASFV VETF in five distinct conformations. The complex adopts an unusual chair-like architecture stabilized by an extensive buried interfacial area. The small subunit, pD1133L, contains a conserved SF2 ATPase core and mutational analyses confirm the functional importance of its catalytic motifs. A positively charged surface channel in pD1133L is consistent with a potential DNA-binding site, supported by the DNA-binding activity of both pD1133L and the VETF heterodimer. In the apo structures, this channel is positioned against the N-terminal domain (NTD) of pG1340L suggesting that NTD rearrangement may modulate DNA accessibility. The five reconstructions further reveal substantial mobility of the pG1340L NTD and Domain 4, while Domain 3 remains conformationally flexible. Comparison and modeling with the ASFV transcription machinery indicate that the observed apo arrangement is unfavorable for formation of a PIC-like complex. Together, these findings define the architecture and conformational landscape of ASFV VETF and provide a structural framework for understanding how its conformational rearrangements may contribute to promoter recognition and transcription initiation. These findings may also support the development of antiviral strategies targeting VETF activation. PubMed: 42833331DOI: 10.1016/j.ijbiomac.2026.154747 PDB entries with the same primary citation |
| Experimental method | ELECTRON MICROSCOPY (4 Å) |
Structure validation
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