single letter bases

skspoidn at skspoidn at
Fri Apr 2 16:37:14 EST 1993

re base nomenculature...

How do we remember what is what?...

A, G, C, T, U are obvious

For a base which is one of three, use the letter after the base concerned. ie

V=NOT T (U is already Uridine)

S=GC, W=AT...S stands for strong, W for weak,
 correspondong to 3 or 2 H bonds and the strength 
of the pairing in the link.

R=purine...short name, large base ie A or G
Y=Pyrimidine... long name, small base ie C or T

That leaves K (keto) which is G or T
M (which means methyl) and is A or C

Personally, I find all of these easy to remember except K vs M.
 The mnemonic I use here is that since G can be methylated, 
it must start out Ketone (ie K), 
and from this all others can be derived :)

so John Nash got it right, but I hope the reasoning helps you remember :)

Mike "kitkitkitkitkitkitkitkitkit" Poidinger
Dept Of Microbiology
University of Reading

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