 |
PDBsum entry 4qu4
|
|
|
|
References listed in PDB file
|
 |
|
Key reference
|
|
|
Title
|
|
The mtr4 ratchet helix and arch domain both function to promote RNA unwinding.
|
|
|
Authors
|
|
L.L.Taylor,
R.N.Jackson,
M.Rexhepaj,
A.K.King,
L.K.Lott,
A.Van hoof,
S.J.Johnson.
|
|
|
Ref.
|
|
Nucleic Acids Res, 2014,
42,
13861-13872.
[DOI no: ]
|
|
|
PubMed id
|
|
|
|
|
|
Abstract
|
|
|
Mtr4 is a conserved Ski2-like RNA helicase and a subunit of the TRAMP complex
that activates exosome-mediated 3'-5' turnover in nuclear RNA surveillance and
processing pathways. Prominent features of the Mtr4 structure include a
four-domain ring-like helicase core and a large arch domain that spans the core.
The 'ratchet helix' is positioned to interact with RNA substrates as they move
through the helicase. However, the contribution of the ratchet helix in Mtr4
activity is poorly understood. Here we show that strict conservation along the
ratchet helix is particularly extensive for Ski2-like RNA helicases compared to
related helicases. Mutation of residues along the ratchet helix alters in vitro
activity in Mtr4 and TRAMP and causes slow growth phenotypes in vivo. We also
identify a residue on the ratchet helix that influences Mtr4 affinity for
polyadenylated substrates. Previous work indicated that deletion of the arch
domain has minimal effect on Mtr4 unwinding activity. We now show that combining
the arch deletion with ratchet helix mutations abolishes helicase activity and
produces a lethal in vivo phenotype. These studies demonstrate that the ratchet
helix modulates helicase activity and suggest that the arch domain plays a
previously unrecognized role in unwinding substrates.
|
|
|
Secondary reference #1
|
|
|
Title
|
|
The crystal structure of mtr4 reveals a novel arch domain required for rrna processing.
|
|
|
Authors
|
|
R.N.Jackson,
A.A.Klauer,
B.J.Hintze,
H.Robinson,
A.Van hoof,
S.J.Johnson.
|
|
|
Ref.
|
|
Embo J, 2010,
29,
2205-2216.
|
|
|
PubMed id
|
|
|
|
|
|
|
|
|
|
|
|
|
