Bentley A Fane

Bentley A Fane

Professor, Plant Sciences
Professor, Applied BioSciences - GIDP
Professor, Genetics - GIDP
Professor, Immunobiology
Professor, BIO5 Institute
Primary Department
Department Affiliations
Contact
(520) 626-6634

Work Summary

Upon infection, viruses must transport their genomes into cells and produce progeny, often under a strict time deadline. We study how the viral proteins interact with with each other and with host cell proteins to efficiently accomplish these processes.

Research Interest

Bentley A. Fane, PhD, is a Professor in the School of Plant Sciences, College of Agriculture and Life Sciences and holds a joint appointment in the Department of Immunobiology, Arizona College of Medicine. Dr. Fane has an international reputation for his research into virus structure, assembly and evolution. His research focuses on the viruses of the Microviridae, of which he is considered one of the leading experts. He has been instrumental in defining the biochemical and structural parameters that allow these viruses to replicate and produce progeny in as little as five minutes. The rapid lifecycle has facilitated in depth studies into how viruses evolved resistance mechanism to anti-viral proteins targeting particle assembly.He has published over 60 original research paper in leading scientific journals, including Nature, Molecular Cell, and Journal of Virology, in which his publications on the evolution of resistance mechanisms and kinetic traps have been selected by the journal editors as articles of “significant interest.” He is a frequent presenter at national and international meetings, and has been invited to State of the Art and plenary talks at give the American Society for Virology. He presently serves on the Editorial Boards of two leading virology journals: Virology and the Journal of Virology. At the University of Arizona, Dr. Fane has been actively involved in promoting undergraduate research has been honored with teaching awards on the department, college, and university levels. Keywords: Virus structure and assembly, Viral DNA translocation, Viral evolution

Publications

Brentlinger, K. L., Hafenstein, S., Novak, C. R., Fane, B. A., Borgon, R., McKenna, R., & Agbandje-McKenna, M. (2002). Microviridae, a family divided: Isolation, characterization, and genome sequence of φMH2K, a bacteriophage of the obligate intracellular parasitic bacterium Bdellovibrio bacteriovorus. Journal of Bacteriology, 184(4), 1089-1094.

PMID: 11807069;PMCID: PMC134817;Abstract:

A novel single-stranded DNA phage, φMH2K, of Bdellovibrio bacteriovorus was isolated, characterized, and sequenced. This phage is a member of the Microviridae, a family typified by bacteriophage φX174. Although B. bacteriovorus and Escherichia coli are both classified as proteobacteria, φMH2K is only distantly related to φX174. Instead, φMH2K exhibits an extremely close relationship to the Microviridae of Chlamydia in both genome organization and encoded proteins. Unlike the double-stranded DNA bacteriophages, for which a wide spectrum of diversity has been observed, the single-stranded icosahedral bacteriophages appear to fall into two distinct subfamilies. These observations suggest that the mechanisms driving single-stranded DNA bacteriophage evolution are inherently different from those driving the evolution of the double-stranded bacteriophages.

Fane, B., Uchiyama, A., & Fane, B. A. (2005). Identification of an interacting coat-external scaffolding protein domain required for both the initiation of phiX174 procapsid morphogenesis and the completion of DNA packaging. Journal of virology, 79(11).

The phiX174 external scaffolding protein D mediates the assembly of coat protein pentamers into procapsids. There are four external scaffolding subunits per coat protein. Organized as pairs of asymmetric dimers, the arrangement is unrelated to quasi-equivalence. The external scaffolding protein contains seven alpha-helices. The protein's core, alpha-helices 2 to 6, mediates the vast majority of intra- and interdimer contacts and is strongly conserved in all Microviridae (canonical members are phiX174, G4, and alpha3) external scaffolding proteins. On the other hand, the primary sequences of the first alpha-helices have diverged. The results of previous studies with alpha3/phiX174 chimeric external scaffolding proteins suggest that alpha-helix 1 may act as a substrate specificity domain, mediating the initial coat scaffolding protein recognition in a species-specific manner. However, the low sequence conservation between the two phages impeded genetic analyses. In an effort to elucidate a more mechanistic model, chimeric external scaffolding proteins were constructed between the more closely related phages G4 and phiX174. The results of biochemical analyses indicate that the chimeric external scaffolding protein inhibits two morphogenetic steps: the initiation of procapsid formation and DNA packaging. phiX174 mutants that can efficiently utilize the chimeric protein were isolated and characterized. The substitutions appear to suppress both morphogenetic defects and are located in threefold-related coat protein sequences that most likely form the pores in the viral procapsid. These results identify coat-external scaffolding domains needed to initiate procapsid formation and provide more evidence, albeit indirect, that the pores are the site of DNA entry during the packaging reaction.

Uchiyama, A., & Fane, B. A. (2005). Identification of an interacting coat-external scaffolding protein domain required for both the initiation of φX174 procapsid morphogenesis and the completion of DNA packaging. Journal of Virology, 79(11), 6751-6756.

PMID: 15890913;PMCID: PMC1112155;Abstract:

The φX174 external scaffolding protein D mediates the assembly of coat protein pentamers into procapsids. There are four external scaffolding subunits per coat protein. Organized as pairs of asymmetric dimers, the arrangement is unrelated to quasi-equivalence. The external scaffolding protein contains seven α-helices. The protein's core, α-helices 2 to 6, mediates the vast majority of intra- and interdimer contacts and is strongly conserved in all Microviridae (canonical members are φX174, G4, and α3) external scaffolding proteins. On the other hand, the primary sequences of the first α-helices have diverged. The results of previous studies with α3/φX174 chimeric external scaffolding proteins suggest that α-helix 1 may act as a substrate specificity domain, mediating the initial coat scaffolding protein recognition in a species-specific manner. However, the low sequence conservation between the two phages impeded genetic analyses. In an effort to elucidate a more mechanistic model, chimeric external scaffolding proteins were constructed between the more closely related phages G4 and αX174. The results of biochemical analyses indicate that the chimeric external scaffolding protein inhibits two morphogenetic steps: the initiation of procapsid formation and DNA packaging. φX174 mutants that can efficiently utilize the chimeric protein were isolated and characterized. The substitutions appear to suppress both morphogenetic defects and are located in threefold-related coat protein sequences that most likely form the pores in the viral procapsid. These results identify coat-external scaffolding domains needed to initiate procapsid formation and provide more evidence, albeit indirect, that the pores are the site of DNA entry during the packaging reaction. Copyright © 2005, American Society for Microbiology. All Rights Reserved.

Ekechukwu, M. C., & Fane, B. A. (1995). Characterization of the morphogenetic defects conferred by cold-sensitive prohead accessory and scaffolding proteins of φX174. Journal of Bacteriology, 177(3), 829-830.

PMID: 7836321;PMCID: PMC176665;Abstract:

The morphogenetic defects conferred by the cold-sensitive prohead accessory and scaffolding proteins of φX174 were determined in vivo. The results suggest that the cold-sensitive prohead accessory protein blocks the formation of the 12S assembly intermediate. The cold-sensitive scaffolding protein most likely affects the stability of the prohead.

Fane, B., Uchiyama, A., Heiman, P., & Fane, B. A. (2009). N-terminal deletions of the phiX174 external scaffolding protein affect the timing and fidelity of assembly. Virology, 386(2).

The first alpha-helices of Microviridae external scaffolding proteins function as coat protein substrate specificity domains. Mutations in this helix can lengthen the lag phase before progeny production. 5' deletion genes, encoding N-terminal deletion proteins, were constructed on plasmids and in the øX174 genome. Proteins lacking the first seven amino acids were able to rescue a nullD mutant when expressed from a plasmid. However, the lag phase before progeny production was lengthened. The øX174 mutant with the corresponding genomic gene grew very poorly. The molecular basis of the defective phenotype was complex. External scaffolding protein levels were reduced compared to wild-type and most of the viral coat protein in mutant infected cells appears to be siphoned off the assembly pathway. Second-site suppressors of the growth defects were isolated and appear to act via two different mechanisms. One class of suppressors most likely acts by altering mutant external scaffolding protein expression while the second class of suppressors appears to act on the level of protein-protein interactions.