Acyltransferase involved in the biosynthesis of lignin. The affinity for shikimate as acceptor is 100-fold higher than for quinate. The most efficient donors are caffeoyl-CoA > p-coumaroyl-CoA > feruloyl-CoA >> sinapoyl-CoA. 4-coumaroyl-CoA + shikimate = CoA + trans-4-coumaroylshikimate Highly expressed in stem vascular tissues. Belongs to the plant acyltransferase family.