Structure/function insights into Tn5 transposition

Steiniger-White, Mindy; Rayment, Ivan; Reznikoff, William S.

doi:10.1016/j.sbi.2004.01.008

Cited by 76 publications

(83 citation statements)

References 39 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Rather, our results demonstrate that the presence of an intact L1/R1 subunit pair is necessary to maintain the stability of the complex. The stability provided by the L1/ R1 MuA interaction pair may mimic transposition complexes such as the Tn5 transpososome, which is a stable dimer both during and after the transposition reaction (23). Additionally, our results are supported by cryo electron-microscopy data, which reveal extensive protein-protein contacts unique to the two catalytic subunits in a double right-end Mu complex (20).…”

Section: Discussion Clpx As a Machine For Disassembly Of Macromoleculsupporting

confidence: 67%

The AAA+ ClpX machine unfolds a keystone subunit to remodel the Mu transpososome

Abdelhakim

Sauer

Baker

2010

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

A hyperstable complex of the tetrameric MuA transposase with recombined DNA must be remodeled to allow subsequent DNA replication. ClpX, a AAAþ enzyme, fulfills this function by unfolding one transpososome subunit. Which MuA subunit is extracted, and how complex destabilization relates to establishment of the correct directionality (left to right) of Mu replication, is not known. Here, using altered-specificity MuA proteins/DNA sites, we demonstrate that transpososome destabilization requires preferential ClpX unfolding of either the catalytic-left or catalytic-right subunits, which make extensive intersubunit contacts in the tetramer. In contrast, ClpX recognizes the other two subunits in the tetramer much less efficiently, and their extraction does not substantially destabilize the complex. Thus, ClpX targets the most stable structural components of the complex. Left-end biased Mu replication is not, however, determined by ClpX's intrinsic subunit preference. The specific targeting of a stabilizing "keystone subunit" within a complex for unfolding is an attractive general mechanism for remodeling by AAAþ enzymes.

show abstract

Section: Discussion Clpx As a Machine For Disassembly Of Macromoleculsupporting

confidence: 67%

The AAA+ ClpX machine unfolds a keystone subunit to remodel the Mu transpososome

Abdelhakim

Sauer

Baker

2010

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

show abstract

“…The transposase DDE domain contains a motif of three conserved carboxylate residues (DDE), which are thought to be responsible for coordinating metal ions needed for catalysis. This has been shown conclusively in the E. coli Tnp Tn5 structure (33).…”

Section: Resultsmentioning

confidence: 52%

Acinetobacter Insertion Sequence IS Aba11 Belongs to a Novel Family That Encodes Transposases with a Signature HHEK Motif

Rieck¹,

Tourigny²,

Crosatti³

et al. 2012

Appl Environ Microbiol

View full text Add to dashboard Cite

Experimental and in silico PCR analysis targeting ISAba11 and TnAbaR islands in 196 epidemiologically unrelatedAcinetobacter strains representative of >19 species were performed. The first two Acinetobacter baumannii ISAba11 elements identified had been found to map to the same site on TnAbaR transposons. However, no further evidence of physical linkage between the two elements was demonstrated. Indeed, examination of 25 definite or putative insertion sites suggested limited sequence specificity. Importantly, an aacC1-tagged version of ISAba11 was shown to actively transpose in A. baumannii. Similarity searches identified nine iso-ISAba11 elements in Acinetobacter and one in Enhydrobacter and single representatives of four distant homologs in bacteria belonging to the phyla "Cyanobacteria" and Proteobacteria. Phylogenetic, sequence, and structural analyses of ISAba11 and/or its associated transposase (Tnp ISAba11 ) suggested that these elements be assigned to a new family. All five homologs encode transposases with a shared extended signature comprising 16 invariant residues within the N2, N3, and C1 regions, four of which constituted the cardinal ISAba11 family HHEK motif that is substituted for the YREK DNA binding motif conserved in the IS4 family. Additionally, ISAba11 family members were associated with either no flanking direct repeat (DR) or an ISAba11-typical 5-bp DR and possessed variable-length terminal inverted repeats that exhibited extensive intrafamily sequence identity. Given the limited pairwise identity among Tnp ISAba11 homologs and the observed restricted distribution of ISAba11, we propose that substantial gaps persist in the evolutionary record of ISAba11 and that this element represents a recent though potentially highly significant entrant into the A. baumannii gene pool.

show abstract

“…The INT domain of the EP retroelements (reverse-transcribing viruses) is a member of the DDE (named after the distinct catalytic triad) family of transposases that mediate the transposition of numerous DNA transposons in prokaryotes and eukaryotes (112)(113)(114). Therefore, the founder of the EP (LTR) retrotransposon branch most likely evolved through recombination between a TP (non-LTR) retrotransposon and a DNA transposon (115,116).…”

Section: Retroelements and Retroviruses: Viruses As Derived Formsmentioning

confidence: 99%

Virus World as an Evolutionary Network of Viruses and Capsidless Selfish Elements

Koonin

Dolja

2014

Microbiol Mol Biol Rev

215

211

View full text Add to dashboard Cite

SUMMARY Viruses were defined as one of the two principal types of organisms in the biosphere, namely, as capsid-encoding organisms in contrast to ribosome-encoding organisms, i.e., all cellular life forms. Structurally similar, apparently homologous capsids are present in a huge variety of icosahedral viruses that infect bacteria, archaea, and eukaryotes. These findings prompted the concept of the capsid as the virus “self” that defines the identity of deep, ancient viral lineages. However, several other widespread viral “hallmark genes” encode key components of the viral replication apparatus (such as polymerases and helicases) and combine with different capsid proteins, given the inherently modular character of viral evolution. Furthermore, diverse, widespread, capsidless selfish genetic elements, such as plasmids and various types of transposons, share hallmark genes with viruses. Viruses appear to have evolved from capsidless selfish elements, and vice versa, on multiple occasions during evolution. At the earliest, precellular stage of life's evolution, capsidless genetic parasites most likely emerged first and subsequently gave rise to different classes of viruses. In this review, we develop the concept of a greater virus world which forms an evolutionary network that is held together by shared conserved genes and includes both bona fide capsid-encoding viruses and different classes of capsidless replicons. Theoretical studies indicate that selfish replicons (genetic parasites) inevitably emerge in any sufficiently complex evolving ensemble of replicators. Therefore, the key signature of the greater virus world is not the presence of a capsid but rather genetic, informational parasitism itself, i.e., various degrees of reliance on the information processing systems of the host.

show abstract

Structure/function insights into Tn5 transposition

Cited by 76 publications

References 39 publications

The AAA+ ClpX machine unfolds a keystone subunit to remodel the Mu transpososome

The AAA+ ClpX machine unfolds a keystone subunit to remodel the Mu transpososome

Acinetobacter Insertion Sequence IS Aba11 Belongs to a Novel Family That Encodes Transposases with a Signature HHEK Motif

Virus World as an Evolutionary Network of Viruses and Capsidless Selfish Elements

Contact Info

Product

Resources

About