Demonstration of the covalent loading of the HMWP1 fragments with
L-[35S]cysteine catalyzed by HMWP2 1–1491.
(A) Coomassie-stained gel of TCA-precipitated
reaction mixtures. (B) Autoradiograph of the gel. All
reaction mixtures contained one holo-HMWP1 fragment (1 μM), HMWP1
1–1491 (0.15 μM), and [35S]cysteine (100 μM, 285
Ci/mol). ATP was omitted in the odd-numbered lanes and added (2 mM) in
the even-numbered lanes except lane 0. Lane 0, molecular weight
markers; lanes 1 and 2, holo-1–1895; lanes 3 and 4, holo-1812–3163;
lanes 5 and 6, holo-1896–3163.