Cysteine residue, biotinylation

The above aflSnity labeling reagents were found to inhibit specifically the uptake of biotin, but not other nutrients, into yeast cells. From the reactivation studies, one can conclude that an essential cysteine or histidine residue was modified in the transport system. The biotinylated protein can be specifically adsorbed to avidin columns, and subsequent elution with thiols should yield biotin transport component (s) in an active form. 

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