Download MendeleyStructure and Activity of a Novel Archaeal Beta-Casp Protein with N-Terminal Kh Domains.
Silva, A.P.G., Chechik, M., Byrne, R.T., Waterman, D.G., Ng, C.L., Dodson, E.J., Koonin, E.V., Antson, A.A., Smits, C.(2011) Structure 19: 622
- PubMed: 21565697
- DOI: https://doi.org/10.1016/j.str.2011.03.002
- Primary Citation of Related Structures:
2YCB - PubMed Abstract:
MTH1203, a β-CASP metallo-β-lactamase family nuclease from the archaeon Methanothermobacter thermautotrophicus, was identified as a putative nuclease that might contribute to RNA processing. The crystal structure of MTH1203 reveals that, in addition to the metallo-β-lactamase nuclease and the β-CASP domains, it contains two contiguous KH domains that are unique to MTH1203 and its orthologs. RNA-binding experiments indicate that MTH1203 preferentially binds U-rich sequences with a dissociation constant in the micromolar range. In vitro nuclease activity assays demonstrated that MTH1203 is a zinc-dependent nuclease. MTH1203 is also shown to be a dimer and, significantly, this dimerization enhances the nuclease activity. Transcription termination in archaea produces mRNA transcripts with U-rich 3' ends that could be degraded by MTH1203 considering its RNA-binding specificity. We hypothesize that this nuclease degrades mRNAs of proteins targeted for degradation and so regulates archaeal RNA turnover, possibly in concert with the exosome.
Organizational Affiliation:
York Structural Biology Laboratory, Department of Chemistry, University of York, York YO10 5YW, United Kingdom.
