Conformational changes in the expression domain of the Escherichia coli thiM riboswitch

نویسندگان

  • Andrea Rentmeister
  • Günter Mayer
  • Nicole Kuhn
  • Michael Famulok
چکیده

The thiM riboswitch contains an aptamer domain that adaptively binds the coenzyme thiamine pyrophosphate (TPP). The binding of TPP to the aptamer domain induces structural rearrangements that are relayed to a second domain, the so-called expression domain, thereby interfering with gene expression. The recently solved crystal structures of the aptamer domains of the thiM riboswitches in complex with TPP revealed how TPP stabilizes secondary and tertiary structures in the RNA ligand complex. To understand the global modes of reorganization between the two domains upon metabolite binding the structure of the entire riboswitch in presence and absence of TPP needs to be determined. Here we report the secondary structure of the entire thiM riboswitch from Escherichia coli in its TPP-free form and its transition into the TPP-bound variant, thereby depicting domains of the riboswitch that serve as communication links between the aptamer and the expression domain. Furthermore, structural probing provides an explanation for the lack of genetic control exerted by a riboswitch variant with mutations in the expression domain that still binds TPP.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Secondary structures and functional requirements for thiM riboswitches from Desulfovibrio vulgaris, Erwinia carotovora and Rhodobacter spheroides.

Abstract Bacterial thiM riboswitches contain aptamer domains that bind the metabolite thiamine pyrophosphate (TPP). Binding of TPP to the aptamer domain induces structural rearrangements that are relayed to the expression domain, thereby interfering with gene expression. Here, we report identification of three putative thiM riboswitches from different bacteria and analysis of their secondary st...

متن کامل

Ligand-induced folding of the thiM TPP riboswitch investigated by a structure-based fluorescence spectroscopic approach

Riboswitches are genetic control elements within non-coding regions of mRNA. They consist of a metabolite-sensitive aptamer and an adjoining expression platform. Here, we describe ligand-induced folding of a thiamine pyrophosphate (TPP) responsive riboswitch from Escherichia coli thiM mRNA, using chemically labeled variants. Referring to a recent structure determination of the TPP/aptamer compl...

متن کامل

Dual-acting riboswitch control of translation initiation and mRNA decay.

Riboswitches are mRNA regulatory elements that control gene expression by altering their structure in response to specific metabolite binding. In bacteria, riboswitches consist of an aptamer that performs ligand recognition and an expression platform that regulates either transcription termination or translation initiation. Here, we describe a dual-acting riboswitch from Escherichia coli that, ...

متن کامل

A kissing loop is important for btuB riboswitch ligand sensing and regulatory control.

RNA-based genetic regulation is exemplified by metabolite-binding riboswitches that modulate gene expression through conformational changes. Crystal structures show that the Escherichia coli btuB riboswitch contains a kissing loop interaction that is in close proximity to the bound ligand. To analyze the role of the kissing loop interaction in the riboswitch regulatory mechanism, we used RNase ...

متن کامل

Translational control and Rho-dependent transcription termination are intimately linked in riboswitch regulation

Riboswitches are regulatory elements that control gene expression by altering RNA structure upon the binding of specific metabolites. Although Bacillus subtilis riboswitches have been shown to control premature transcription termination, less is known about regulatory mechanisms employed by Escherichia coli riboswitches, which are predicted to regulate mostly at the level of translation initiat...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:

دوره 35  شماره 

صفحات  -

تاریخ انتشار 2007