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Cross-subunit catalysis and a new phenomenon of recessive resurrection in Escherichia coli RNase E.
Nucleic Acids Res 2020; 48(2):847-861NA

Abstract

RNase E is a 472-kDa homo-tetrameric essential endoribonuclease involved in RNA processing and turnover in Escherichia coli. In its N-terminal half (NTH) is the catalytic active site, as also a substrate 5'-sensor pocket that renders enzyme activity maximal on 5'-monophosphorylated RNAs. The protein's non-catalytic C-terminal half (CTH) harbours RNA-binding motifs and serves as scaffold for a multiprotein degradosome complex, but is dispensable for viability. Here, we provide evidence that a full-length hetero-tetramer, composed of a mixture of wild-type and (recessive lethal) active-site mutant subunits, exhibits identical activity in vivo as the wild-type homo-tetramer itself ('recessive resurrection'). When all of the cognate polypeptides lacked the CTH, the active-site mutant subunits were dominant negative. A pair of C-terminally truncated polypeptides, which were individually inactive because of additional mutations in their active site and 5'-sensor pocket respectively, exhibited catalytic function in combination, both in vivo and in vitro (i.e. intragenic or allelic complementation). Our results indicate that adjacent subunits within an oligomer are separately responsible for 5'-sensing and cleavage, and that RNA binding facilitates oligomerization. We propose also that the CTH mediates a rate-determining initial step for enzyme function, which is likely the binding and channelling of substrate for NTH's endonucleolytic action.

Authors+Show Affiliations

Laboratory of Bacterial Genetics, Centre for DNA Fingerprinting and Diagnostics, Hyderabad 500039, India. Graduate Studies, Manipal Academy of Higher Education, Manipal 576104, India.Laboratory of Bacterial Genetics, Centre for DNA Fingerprinting and Diagnostics, Hyderabad 500039, India.

Pub Type(s)

Journal Article

Language

eng

PubMed ID

31802130

Citation

Ali, Nida, and Jayaraman Gowrishankar. "Cross-subunit Catalysis and a New Phenomenon of Recessive Resurrection in Escherichia Coli RNase E." Nucleic Acids Research, vol. 48, no. 2, 2020, pp. 847-861.
Ali N, Gowrishankar J. Cross-subunit catalysis and a new phenomenon of recessive resurrection in Escherichia coli RNase E. Nucleic Acids Res. 2020;48(2):847-861.
Ali, N., & Gowrishankar, J. (2020). Cross-subunit catalysis and a new phenomenon of recessive resurrection in Escherichia coli RNase E. Nucleic Acids Research, 48(2), pp. 847-861. doi:10.1093/nar/gkz1152.
Ali N, Gowrishankar J. Cross-subunit Catalysis and a New Phenomenon of Recessive Resurrection in Escherichia Coli RNase E. Nucleic Acids Res. 2020 Jan 24;48(2):847-861. PubMed PMID: 31802130.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Cross-subunit catalysis and a new phenomenon of recessive resurrection in Escherichia coli RNase E. AU - Ali,Nida, AU - Gowrishankar,Jayaraman, PY - 2019/11/26/accepted PY - 2019/11/21/revised PY - 2019/10/16/received PY - 2019/12/6/pubmed PY - 2019/12/6/medline PY - 2019/12/6/entrez SP - 847 EP - 861 JF - Nucleic acids research JO - Nucleic Acids Res. VL - 48 IS - 2 N2 - RNase E is a 472-kDa homo-tetrameric essential endoribonuclease involved in RNA processing and turnover in Escherichia coli. In its N-terminal half (NTH) is the catalytic active site, as also a substrate 5'-sensor pocket that renders enzyme activity maximal on 5'-monophosphorylated RNAs. The protein's non-catalytic C-terminal half (CTH) harbours RNA-binding motifs and serves as scaffold for a multiprotein degradosome complex, but is dispensable for viability. Here, we provide evidence that a full-length hetero-tetramer, composed of a mixture of wild-type and (recessive lethal) active-site mutant subunits, exhibits identical activity in vivo as the wild-type homo-tetramer itself ('recessive resurrection'). When all of the cognate polypeptides lacked the CTH, the active-site mutant subunits were dominant negative. A pair of C-terminally truncated polypeptides, which were individually inactive because of additional mutations in their active site and 5'-sensor pocket respectively, exhibited catalytic function in combination, both in vivo and in vitro (i.e. intragenic or allelic complementation). Our results indicate that adjacent subunits within an oligomer are separately responsible for 5'-sensing and cleavage, and that RNA binding facilitates oligomerization. We propose also that the CTH mediates a rate-determining initial step for enzyme function, which is likely the binding and channelling of substrate for NTH's endonucleolytic action. SN - 1362-4962 UR - https://www.unboundmedicine.com/medline/citation/31802130/Cross-subunit_catalysis_and_a_new_phenomenon_of_recessive_resurrection_in_Escherichia_coli_RNase_E L2 - https://academic.oup.com/nar/article-lookup/doi/10.1093/nar/gkz1152 DB - PRIME DP - Unbound Medicine ER -