PMID- 36848192
OWN - NLM
STAT- MEDLINE
DCOM- 20230327
LR  - 20230412
IS  - 1537-1719 (Electronic)
IS  - 0737-4038 (Print)
IS  - 0737-4038 (Linking)
VI  - 40
IP  - 3
DP  - 2023 Mar 4
TI  - Fitness and Functional Landscapes of the E. coli RNase III Gene rnc.
LID - 10.1093/molbev/msad047 [doi]
LID - msad047
AB  - How protein properties such as protein activity and protein essentiality affect 
      the distribution of fitness effects (DFE) of mutations are important questions in 
      protein evolution. Deep mutational scanning studies typically measure the effects 
      of a comprehensive set of mutations on either protein activity or fitness. Our 
      understanding of the underpinnings of the DFE would be enhanced by a 
      comprehensive study of both for the same gene. Here, we compared the fitness 
      effects and in vivo protein activity effects of  approximately 4,500 missense mutations in the 
      E. coli rnc gene. This gene encodes RNase III, a global regulator enzyme that 
      cleaves diverse RNA substrates including precursor ribosomal RNA and various 
      mRNAs including its own 5' untranslated region (5'UTR). We find that RNase III's 
      ability to cleave dsRNA is the most important determinant of the fitness effects 
      of rnc mutations. The DFE of RNase III was bimodal, with mutations centered 
      around neutral and deleterious effects, consistent with previously reported DFE's 
      of enzymes with a singular physiological role. Fitness was buffered to small 
      effects on RNase III activity. The enzyme's RNase III domain, which contains the 
      RNase III signature motif and all active site residues, was more sensitive to 
      mutation than its dsRNA binding domain, which is responsible for recognition and 
      binding to dsRNA. Differential effects on fitness and functional scores for 
      mutations at highly conserved residues G97, G99, and F188 suggest that these 
      positions may be important for RNase III cleavage specificity.
CI  - (c) The Author(s) 2023. Published by Oxford University Press on behalf of Society 
      for Molecular Biology and Evolution.
FAU - Weeks, Ryan
AU  - Weeks R
AD  - Chemistry-Biology Interface Graduate Program, Johns Hopkins University, 
      Baltimore, MD, USA.
FAU - Ostermeier, Marc
AU  - Ostermeier M
AUID- ORCID: 0000-0003-0900-3665
AD  - Department of Chemical and Biomolecular Engineering, Johns Hopkins University, 
      Baltimore, MD, USA.
LA  - eng
PT  - Journal Article
PT  - Research Support, U.S. Gov't, Non-P.H.S.
PL  - United States
TA  - Mol Biol Evol
JT  - Molecular biology and evolution
JID - 8501455
RN  - EC 3.1.26.3 (Ribonuclease III)
RN  - 0 (Escherichia coli Proteins)
SB  - IM
MH  - *Escherichia coli/genetics/metabolism
MH  - Ribonuclease III/genetics
MH  - *Escherichia coli Proteins/genetics
MH  - Mutation
PMC - PMC10037077
OTO - NOTNLM
OT  - RNase III
OT  - fitness landscape
OT  - protein evolution
EDAT- 2023/02/28 06:00
MHDA- 2023/03/28 06:00
PMCR- 2023/02/27
CRDT- 2023/02/27 12:04
PHST- 2023/02/28 06:00 [pubmed]
PHST- 2023/03/28 06:00 [medline]
PHST- 2023/02/27 12:04 [entrez]
PHST- 2023/02/27 00:00 [pmc-release]
AID - 7059036 [pii]
AID - msad047 [pii]
AID - 10.1093/molbev/msad047 [doi]
PST - ppublish
SO  - Mol Biol Evol. 2023 Mar 4;40(3):msad047. doi: 10.1093/molbev/msad047.