Sequence of Bacillus subtilis chromosome

Julie Lawrence julie at genbank.bio.net
Tue Oct 22 13:41:00 EST 1991


In response to the following post by Conrad Halling:

> Furthermore, I'd like to point out that it is virtually impossible to
> obtain the accession number of such a "complete" entry if you know only
> that an entry with the sequence of a chromosome of organism X exists.
> Using IRX to search GenBank, the following search strings give the following
> number of hits:

> sequence of Bacillus subtilis chromosome                30,992 entries
> sequence AND Bacillus subtilis AND chromosome              544 entries

I thought it might be useful to point out that these searches
yielded so many hits because of the way they were phrased.  IRX
interprets a phrase such as 'Bacillus subtilis' as an implied 'OR';
thus the queries above are asking for every entry that has either
Bacillus OR subtilis in it--hence, the large number of hits.

If the query is rephrased as:

  sequence AND bacillus AND subtilis AND chromosome

only 26 hits are found--a much more manageable result.

IRX definitely has its shortcomings, but can also be quite powerful
when queries are constructed correctly.

Julie Lawrence
Assistant GenBank Manager
julie at genbank.bio.net



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