Herbert Michael H, Squire Christopher J, Mercer Andrew A
School of Biological Sciences, University of Auckland, Auckland 1010, New Zealand.
Virus Research Unit, Department of Microbiology and Immunology, University of Otago, Dunedin 9016, New Zealand.
Viruses. 2015 Feb 16;7(2):709-38. doi: 10.3390/v7020709.
Multiple repeats of the ankyrin motif (ANK) are ubiquitous throughout the kingdoms of life but are absent from most viruses. The main exception to this is the poxvirus family, and specifically the chordopoxviruses, with ANK repeat proteins present in all but three species from separate genera. The poxviral ANK repeat proteins belong to distinct orthologue groups spread over different species, and align well with the phylogeny of their genera. This distribution throughout the chordopoxviruses indicates these proteins were present in an ancestral vertebrate poxvirus, and have since undergone numerous duplication events. Most poxviral ANK repeat proteins contain an unusual topology of multiple ANK motifs starting at the N-terminus with a C-terminal poxviral homologue of the cellular F-box enabling interaction with the cellular SCF ubiquitin ligase complex. The subtle variations between ANK repeat proteins of individual poxviruses suggest an array of different substrates may be bound by these protein-protein interaction domains and, via the F-box, potentially directed to cellular ubiquitination pathways and possible degradation. Known interaction partners of several of these proteins indicate that the NF-κB coordinated anti-viral response is a key target, whilst some poxviral ANK repeat domains also have an F-box independent affect on viral host-range.
锚蛋白基序（ANK）的多个重复序列在整个生命王国中普遍存在，但大多数病毒中不存在。痘病毒科是主要的例外，特别是脊索痘病毒，除了来自不同属的三个物种外，所有物种中都存在ANK重复蛋白。痘病毒的ANK重复蛋白属于分布在不同物种中的不同直系同源物组，并且与它们所属属的系统发育很好地对齐。这种在脊索痘病毒中的分布表明这些蛋白存在于一种祖先脊椎动物痘病毒中，并且此后经历了许多复制事件。大多数痘病毒ANK重复蛋白包含一种不寻常的拓扑结构，即多个ANK基序从N端开始，其C端是细胞F-box的痘病毒同源物，能够与细胞SCF泛素连接酶复合物相互作用。个别痘病毒的ANK重复蛋白之间的细微差异表明，这些蛋白质-蛋白质相互作用结构域可能结合一系列不同的底物，并通过F-box潜在地导向细胞泛素化途径并可能导致降解。这些蛋白质中的几种已知相互作用伙伴表明，NF-κB协调的抗病毒反应是一个关键靶点，而一些痘病毒ANK重复结构域对病毒宿主范围也有独立于F-box的影响。
