Combinatorial enzymatic complexes

A cell containing a composition comprising:

• a) nucleic acid encoding an exogeneous scaffold comprising at least a first binding site and a second binding site;
• and
• b) nucleic acid encoding at least a first and a second enzyme, wherein at least one of said enzymes is heterologous to said cell;
• wherein said first enzyme is capable of being bound to said first binding site and said second enzyme is capable of being bound to said second binding site.

A method of screening for a bioactive agent, said method comprising:

• a) expressing in a plurality of host cells nucleic acid encoding an exogeneous scaffold comprising at least a first binding site and a second binding site;
• b) expressing in said plurality of host cells nucleic acids encoding at least a first enzyme and a second enzyme;
• under conditions where said nucleic acids are expressed, and said first enzyme binds to said first binding site and said second enzyme binds to said second binding site;
• c) screening said host cells for a cell exhibiting an altered phenotype, wherein said altered phenotype is due to the presence of a bioactive agent.

A method of screening for a bioactive agent, said method comprising:

• a) expressing in a plurality of host cells a library of nucleic acids encoding a library of scaffolds, each scaffold comprising at least a first binding site and a second binding site;
• b) expressing in said cells a library of nucleic acids encoding a library of enzymes;
• under conditions where said nucleic acids are expressed, and at least some of said enzymes bind to said scaffolds;
• c) screening said host cells for an altered phenotype.

A composition comprising:

• a) a scaffold comprising at least a first and a second binding site;
• and
• b) at least a first and a second enzyme;
• wherein said first enzyme is bound to said first binding site and said second enzyme is bound to said second binding site, wherein said enzymes do not biologically react with said scaffold or each other.