β- 和γ- 疱疹病毒以一种与宿主转录不同的方式转录其后期基因。这一过程由病毒转录激活蛋白复合物指导，该复合物劫持了细胞RNA聚合酶II和一些未知的额外因子。我们使用近距离标记结合质谱，以及CRISPR和siRNA筛选来鉴定与Kaposi's sarcoma-associated herpesvirus (KSHV)后期基因转录复合物功能相关的蛋白质。这些数据揭示，病毒DNA包装马达的催化亚单位，ORF29，既与病毒转录激活复合物动态相关，又能加强后期基因表达。通过基因突变和ORF29的删除，我们证明其催化活性加强了病毒转录并且在感染过程中对必要的后期蛋白质的大量积累是必要的。因此，我们提出ORF29的扩展作用，包括其在病毒包装中已经确定的功能以及在KSHV病毒转录和后期基因表达方面的新发现的贡献。版权所有：© 2023 McCollum等人。这是一篇开放获取文章，遵守创作共用许可证，允许在任何媒介中无限制使用、转载和再制，前提是原作者和来源进行了标注。

β- and γ-herpesviruses transcribe their late genes in a manner distinct from host transcription. This process is directed by a complex of viral transcriptional activator proteins that hijack cellular RNA polymerase II and an unknown set of additional factors. We employed proximity labeling coupled with mass spectrometry, followed by CRISPR and siRNA screening to identify proteins functionally associated with the Kaposi's sarcoma-associated herpesvirus (KSHV) late gene transcriptional complex. These data revealed that the catalytic subunit of the viral DNA packaging motor, ORF29, is both dynamically associated with the viral transcriptional activator complex and potentiates late gene expression. Through genetic mutation and deletion of ORF29, we establish that its catalytic activity potentiates viral transcription and is required for robust accumulation of essential late proteins during infection. Thus, we propose an expanded role for ORF29 that encompasses its established function in viral packaging and its newly discovered contributions to viral transcription and late gene expression in KSHV.Copyright: © 2023 McCollum et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.