| getting the best out of long-wavelength x-rays: de novo chlorine/sulfur sad phasing of a structural protein from atv. | the structure of a 14 kda structural protein from acidianus two-tailed virus (atv) was solved by single-wavelength anomalous diffraction (sad) phasing using x-ray data collected at 2.0 a wavelength. although the anomalous signal from methionine sulfurs was expected to suffice to solve the structure, one chloride ion turned out to be essential to achieve phasing. the minimal data requirements and the relative contributions of the cl and s atoms to phasing are discussed. this work supports the fea ... | 2010 | 20179342 |
| chaperone role for proteins p618 and p892 in the extracellular tail development of acidianus two-tailed virus. | the crenarchaeal acidianus two-tailed virus (atv) undergoes a remarkable morphological development, extracellularly and independently of host cells, by growing long tails at each end of a spindle-shaped virus particle. initial work suggested that an intermediate filament-like protein, p800, is involved in this process. we propose that an additional chaperone system is required, consisting of a moxr-type aaa atpase (p618) and a von willebrand domain a (vwa)-containing cochaperone, p892. both prot ... | 2011 | 21367903 |
| aaa atpase p529 of acidianus two-tailed virus atv and host receptor recognition. | the two structural domains of p529, a predicted aaa atpase of acidianus two-tailed virus (atv), were expressed and purified. the n-terminal domain was demonstrated by loss-of-function mutations to carry atpase activity with a temperature optimum of 60°c. this domain also showed dna binding activity that was stronger for the whole protein and was weakened in the presence of atp. the c-terminal domain exhibits mg(2+)-dependent endonuclease activity that was eliminated by site-directed mutagenesis ... | 2011 | 21982819 |
| novel structural and functional insights into the moxr family of aaa+ atpases. | the moxr family of aaa+ atpases is widespread among bacteria and archaea, although their cellular functions are not well characterized. based on recent studies, moxr atpases are proposed to have chaperone-like function for the maturation of specific protein complexes or for the insertion of cofactors into proteins. moxr proteins have been found to be important modulators of multiple stress response pathways in different organisms. for example, the respective moxr proteins have been found to play ... | 2012 | 22491058 |
| crystal structure of atv(orf273), a new fold for a thermo- and acido-stable protein from the acidianus two-tailed virus. | acidianus two-tailed virus (atv) infects crenarchaea of the genus acidianus living in terrestrial thermal springs at extremely high temperatures and low ph. atv is a member of the bicaudaviridae virus family and undergoes extra-cellular development of two tails, a process that is unique in the viral world. to understand this intriguing phenomenon, we have undertaken structural studies of atv virion proteins and here we present the crystal structure of one of these proteins, atv(orf273). atv(orf2 ... | 2012 | 23056221 |
| life cycle characterization of sulfolobus monocaudavirus 1, an extremophilic spindle-shaped virus with extracellular tail development. | we provide here, for the first time, insights into the initial infection stages of a large spindle-shaped archaeal virus and explore the following life cycle events. our observations suggest that sulfolobus monocaudavirus 1 (smv1) exhibits a high adsorption rate and that virions adsorb to the host cells via three distinct attachment modes: nosecone association, body association, and body/tail association. in the body/tail association mode, the entire virion, including the tail(s), aligns to the ... | 2016 | 27053548 |
| repression of rna polymerase by the archaeo-viral regulator orf145/rip. | little is known about how archaeal viruses perturb the transcription machinery of their hosts. here we provide the first example of an archaeo-viral transcription factor that directly targets the host rna polymerase (rnap) and efficiently represses its activity. orf145 from the temperate acidianus two-tailed virus (atv) forms a high-affinity complex with rnap by binding inside the dna-binding channel where it locks the flexible rnap clamp in one position. this counteracts the formation of transc ... | 2016 | 27882920 |