BlastR--fast and accurate database searches for non-coding RNAs

Nucleic Acids Res. 2011 Sep 1;39(16):6886-95. doi: 10.1093/nar/gkr335. Epub 2011 May 30.


We present and validate BlastR, a method for efficiently and accurately searching non-coding RNAs. Our approach relies on the comparison of di-nucleotides using BlosumR, a new log-odd substitution matrix. In order to use BlosumR for comparison, we recoded RNA sequences into protein-like sequences. We then showed that BlosumR can be used along with the BlastP algorithm in order to search non-coding RNA sequences. Using Rfam as a gold standard, we benchmarked this approach and show BlastR to be more sensitive than BlastN. We also show that BlastR is both faster and more sensitive than BlastP used with a single nucleotide log-odd substitution matrix. BlastR, when used in combination with WU-BlastP, is about 5% more accurate than WU-BlastN and about 50 times slower. The approach shown here is equally effective when combined with the NCBI-Blast package. The software is an open source freeware available from

Publication types

  • Research Support, Non-U.S. Gov't
  • Validation Study

MeSH terms

  • Algorithms
  • Databases, Nucleic Acid*
  • RNA, Untranslated / chemistry*
  • Sequence Alignment
  • Sequence Analysis, RNA*
  • Software


  • RNA, Untranslated