Figure 1

Design of the SAPV ( s trept a vidin based p rotein v ector). Biotin (panel A) can routinely and cheaply be included in oligonucleotide primers and thus be easily introduced (in a fully controllable manner) into nucleic acids used for self-assembly. Schematic diagram showing a principle behind the SAPV (panel B). Part of the SAPV DNA (a "double spiral") encodes for a streptavidin protein domain (marked in red) which can bind its own DNA through binding to the biotin molecule (marked green). Protein fragments (and a corresponding DNA fragment) marked in blue – a protein of interest (e.g. displayed peptides or affinity reagents or cloned proteins etc.). Yellow denotes a linker region (both protein and DNA). Streptomyces avidinii gene for streptavidin (X03591) mRNA sequence (panel C). The corresponding deduced amino acid sequence of the streptavidin protein is available from the SwissProt database (P22629). Fragment of the coding region used in the design of the SAPV protein vector is shaded grey.