Isolation of novel single-chain Cro proteins targeted for binding to the bcl-2 transcription initiation site by repertoire selection and subunit combinatorics.

Jonas K, Van Der Vries E, Nilsson MT, Widersten M

Protein Eng. Des. Sel. 18 (11) 537-546 [2005-11-00; online 2005-09-26]

New designed DNA-binding proteins may be recruited to act as transcriptional regulators and could provide new therapeutic agents in the treatment of genetic disorders such as cancer. We have isolated tailored DNA-binding proteins selected for affinity to a region spanning the transcription initiation site of the human bcl-2 gene. The proteins were derived from a single-chain derivative of the lambda Cro protein (scCro), randomly mutated in its recognition helices to construct libraries of protein variants of distinct DNA-binding properties. By phage display-afforded affinity selections combined with recombination of shuffled subunits, protein variants were isolated, which displayed high affinity for the target bcl-2 sequence, as determined by electrophoretic mobility shift and biosensor assays. The proteins analyzed were moderately sequence-specific but provide a starting point for further maturation of desired function.

Kristina Jonas

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PubMed 16186141

DOI 10.1093/protein/gzi058

Crossref 10.1093/protein/gzi058

pii: gzi058