title: Nature's favorite building block: Deciphering folding and capsid assembly of proteins with the HK97-fold.
abstract: For many (if not all) bacterial and archaeal tailed viruses and eukaryotic Herpesvirdae the HK97-fold serves as the major architectural element in icosahedral capsid formation while still enabling the conformational flexibility required during assembly and maturation. Auxiliary proteins or Δ-domains strictly control assembly of multiple, identical, HK97-like subunits into procapsids with specific icosahedral symmetries, rather than aberrant non-icosahedral structures. Procapsids are precursor structures that mature into capsids in a process involving release of auxiliary proteins (or cleavage of Δ-domains), dsDNA packaging, and conformational rearrangement of the HK97-like subunits. Some coat proteins built on the ubiquitous HK97-fold also have accessory domains or loops that impart specific functions, such as increased monomer, procapsid, or capsid stability. In this review, we analyze the numerous HK97-like coat protein structures that are emerging in the literature (over 40 at time of writing) by comparing their topology, additional domains, and their assembly and misassembly reactions.
authors: Department of Molecular and Cell Biology, University of Connecticut, 91N. Eagleville Rd. Storrs, CT 06269-3125, USA. Electronic address: msuhanovsky@colgate.edu.
authors: Margaret M
authors: MM
authors: Suhanovsky
authors: Department of Molecular and Cell Biology, University of Connecticut, 91N. Eagleville Rd. Storrs, CT 06269-3125, USA; Department of Chemistry, University of Connecticut, 91N. Eagleville Rd. Storrs, CT 06269-3125, USA. Electronic address: teschke@uconn.edu.
authors: Carolyn M
authors: CM
authors: Teschke
mesh_terms: D023641:Archaeal Viruses / Q000502:physiology*; D001435:Bacteriophages / Q000502:physiology*; D036022:Capsid Proteins / Q000737:chemistry / Q000378:metabolism*; D006564:Herpesviridae / Q000502:physiology*; D017510:Protein Folding; D055503:Protein Multimerization; D019065:Virus Assembly
chemical_list: D036022:Capsid Proteins
keywords: Accessory domain; Bacteriophage; Capsid protein structure; Coat protein; HK97-fold