Fig 1: Cdc37 and St13, co-chaperones of Hsp90 and Hsc70, interact with the MTS. BpA-containing pOTC mutants were produced in RRL and cross-linked with UV. Fully denatured samples (top gels) or native samples (bottom gels) were then immunoprecipitated with antibodies against Cdc37 (A) or Fkbp5 (B) and analyzed by SDS–PAGE. (C) In vitro translated, BpA-containing pOTC was fractionated on a 5–25% sucrose gradient followed by UV cross-linking of individual fractions. Samples were analyzed by SDS–PAGE. Two independent cross-links migrating close to each other on the gel are marked with red and blue arrows. (D) FL-pOTC containing BpA at position F3 was translated in vitro in the presence or absence of geldanamycin. Samples were then cross-linked with UV, immunoprecipitated with antibody against Cdc37 and analyzed by autoradiography. (E) FL-pOTC containing BpA at positions F3 or H18 were translated in vitro, cross-linked with UV and analyzed by autoradiography. (F) FL-pOTC-H18 was translated in vitro, and purified with an antibody against Hsc70 under native conditions. (G) FL-pOTC-H18 was translated in vitro, cross-linked, and purified with an antibody against St13 under denaturing conditions.