Unknown

Dataset Information

0

Mn(2+)-sensing mechanisms of yybP-ykoY orphan riboswitches.


ABSTRACT: Gene regulation in cis by riboswitches is prevalent in bacteria. The yybP-ykoY riboswitch family is quite widespread, yet its ligand and function remained unknown. Here, we characterize the Lactococcus lactis yybP-ykoY orphan riboswitch as a Mn(2+)-dependent transcription-ON riboswitch, with a ?30-40 ?M affinity for Mn(2+). We further determined its crystal structure at 2.7 Å to elucidate the metal sensing mechanism. The riboswitch resembles a hairpin, with two coaxially stacked helices tethered by a four-way junction and a tertiary docking interface. The Mn(2+)-sensing region, strategically located at the highly conserved docking interface, has two metal binding sites. Whereas one site tolerates the binding of either Mg(2+) or Mn(2+), the other site strongly prefers Mn(2+) due to a direct contact from the N7 of an invariable adenosine. Mutagenesis and a Mn(2+)-free E. coli yybP-ykoY structure further reveal that Mn(2+) binding is coupled with stabilization of the Mn(2+)-sensing region and the aptamer domain.

SUBMITTER: Price IR 

PROVIDER: S-EPMC4703321 | biostudies-literature | 2015 Mar

REPOSITORIES: biostudies-literature

altmetric image

Publications

Mn(2+)-sensing mechanisms of yybP-ykoY orphan riboswitches.

Price Ian R IR   Gaballa Ahmed A   Ding Fang F   Helmann John D JD   Ke Ailong A  

Molecular cell 20150301 6


Gene regulation in cis by riboswitches is prevalent in bacteria. The yybP-ykoY riboswitch family is quite widespread, yet its ligand and function remained unknown. Here, we characterize the Lactococcus lactis yybP-ykoY orphan riboswitch as a Mn(2+)-dependent transcription-ON riboswitch, with a ∼30-40 μM affinity for Mn(2+). We further determined its crystal structure at 2.7 Å to elucidate the metal sensing mechanism. The riboswitch resembles a hairpin, with two coaxially stacked helices tethered  ...[more]

Similar Datasets

| S-EPMC3098680 | biostudies-literature
| S-EPMC2933830 | biostudies-literature
| S-EPMC2258182 | biostudies-literature
| S-EPMC6535548 | biostudies-literature
| S-EPMC6140456 | biostudies-literature
| S-EPMC5340920 | biostudies-literature
| S-EPMC515253 | biostudies-literature
| S-EPMC10140043 | biostudies-literature
| S-EPMC2668411 | biostudies-literature
| S-EPMC4211393 | biostudies-literature