Assembly standard 23/Overview
Pam Silver's lab has developed Assembly standard 23, often called the Silver standard, for assembling protein domains. It relies on shortening the BioBrick prefix and suffix each by 1 base pair such that the resulting SpeI-XbaI scar is only 6 base pairs long and protein domains can be assembled in frame.
As shown in figure 3 (right), Assembly standard 23 results in the inclusion of a Thr-Arg (ACT AGA) two amino acid junction between protein domains.
One disadvantage of the Assembly standard 23 is that the codon AGA which encodes Arginine is a rare codon in E. coli. Rare codons can prevent over-expression of proteins in E. coli.
See [http://openwetware.org/wiki/The_BioBricks_Foundation:Standards/Technical/Formats The BioBricks Foundation wiki] for a discussion and comparison of different technical standards.