Re-engineering of the phosphorylation
site specificity of Pim1.
(A) Peptide array analysis of Pim1 mutants showing specificity at
the −5 position. Spot intensities reflect the extent of phosphorylation
using radiolabeled ATP. pT, phosphothreonine; pY, phosphotyrosine.
(B) Quantitative phosphorylation parameters for Pim1 and quadruple
mutants on peptide substrates assessed by radiolabel kinase assay.
LPVT, Pim1-T134L/D170P/D234 V/D239T; LPIY, Pim1-T134L/D170P/D234I/D239Y;
VPIY, Pim1-T134 V/D170P/D234I/D239Y; LPTY, Pim1-T134L/D170P/D234T/D239Y.
Error bars indicate standard deviation (n = 3).