[BioPython] bioperl idl

John P. Corradi jpc@informatics.jax.org
Mon, 20 Sep 1999 12:16:06 -0400

>>   What I don't understand is how both the strand and complementary strand
>> can code for proteins?
>Typically only one of them (the one with a recognizable promoter) is used
>in transcription.  However, sometimes it's possible to insert a promoter
>upstream of the complementary strand.  This will cause both strands to be
>expressed, resulting in complementary mRNAs that bind to each other,
>preventing translation into proteins.  This is often used in genetically
>engineered food, say, to knock out the gene for senescence, allowing the
>product to mature longer.  Pretty cool stuff.

Hi All,

I'm a biologist who's new to bioinformatics, OOP, and Python (although it's
amazing how quickly you can be productive in Python!).  I'll probably just
lurk for a while, but hopefully I'll be able to contribute in the
not-too-distant future.

It's also important to distinguish between + and - strands for the purposes
of finding open reading frames, translation, generation of hybridization
probes, and sequencing and PCR primers.  Some of the cloning vectors used
to isolate cDNA's are not unidirectional, so when looking for hypothetical
amino acid sequence you would want to translate in all reading frames on
both strands (e.g. blastx on Genbank).  Hybridization probes for detecting
expression are generated from the non-coding (antisense) strand, as are
some oligonucleotide primers used for sequencing and PCR amplification.