Initial Biochemical and Structural Characterization of the Frequency-interacting RNA Helicase, an Mtr4 homolog

Class

Article

Department

Chemistry and Biochemistry

Faculty Mentor

Sean Johnson

Presentation Type

Poster Presentation

Abstract

The frequency-interacting RNA Helicase (FRH) is a Ski2-like helicase from the fungal organism Neurospora crassa. A unique characteristic of FRH is that it participates in both the circadian rhythm and RNA surveillance pathways of N. crassa. FRH is also predicted to be similar to Mtr4, another Ski2-like helicase from Saccharomyces cerevisiae, sharing 73% similarity and 55% identity in primary sequence alignments. FRH is an essential helicase that participates in exosomal complexes similar to those found with Mtr4. Structurally, FRH is expected to maintain the same 5-domain architecture seen in Mtr4, including a large arch domain. Currently, the structural necessity and function of the arch domain is poorly understood. Previous studies have elucidated two possible arch binding partners for FRH named white collar 1 (WC-1) and white collar 2 (WC-2). These white collar proteins are of interest due to their ability to interact with the FRH being abolished when the arch is mutated. Interestingly, both of these white collar proteins are involved in the circadian rhythm of N. crassa as transcription activators and are known to form a white collar complex (WCC) together. Thus, FRH presents a unique opportunity to examine potential protein-protein interactions with the arch domain. In an effort to obtain crystal structures of FRH, crystallization conditions have been identified and are currently being optimized. Also, the development of WCC expression constructs is underway. From this work, it is hypothesized that elucidating and studying the structure of FRH along with these possible white collar protein interactions will clarify a functional role for the arch domain.

Start Date

4-9-2015 1:30 PM

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Apr 9th, 1:30 PM

Initial Biochemical and Structural Characterization of the Frequency-interacting RNA Helicase, an Mtr4 homolog

The frequency-interacting RNA Helicase (FRH) is a Ski2-like helicase from the fungal organism Neurospora crassa. A unique characteristic of FRH is that it participates in both the circadian rhythm and RNA surveillance pathways of N. crassa. FRH is also predicted to be similar to Mtr4, another Ski2-like helicase from Saccharomyces cerevisiae, sharing 73% similarity and 55% identity in primary sequence alignments. FRH is an essential helicase that participates in exosomal complexes similar to those found with Mtr4. Structurally, FRH is expected to maintain the same 5-domain architecture seen in Mtr4, including a large arch domain. Currently, the structural necessity and function of the arch domain is poorly understood. Previous studies have elucidated two possible arch binding partners for FRH named white collar 1 (WC-1) and white collar 2 (WC-2). These white collar proteins are of interest due to their ability to interact with the FRH being abolished when the arch is mutated. Interestingly, both of these white collar proteins are involved in the circadian rhythm of N. crassa as transcription activators and are known to form a white collar complex (WCC) together. Thus, FRH presents a unique opportunity to examine potential protein-protein interactions with the arch domain. In an effort to obtain crystal structures of FRH, crystallization conditions have been identified and are currently being optimized. Also, the development of WCC expression constructs is underway. From this work, it is hypothesized that elucidating and studying the structure of FRH along with these possible white collar protein interactions will clarify a functional role for the arch domain.