Comprehensive analysis of CXXX sequence space reveals that S. cerevisiae GGTase-I mainly relies on a 2 X substrate determinants.

This work investigates yeast GGTase-I specificity through genetics, high throughput sequencing, and two distinct reporter systems. This approach allows for comprehensive evaluation of all CXXX sequence space, which has not been possible with earlier approaches. We identified CXXX sequences supporting geranylgeranylation that differ from the historically defined CaaL sequence often cited in the literature as the GGTase-I target motif, and our results indicate that the last two amino acids of the target motif largely dictate GGTase-I specificity.