The integral membrane enzyme PagP alternates between two dynamically distinct states

PhoPQ-activated gene P (PagP) is an integral membrane enzyme that transfers the sn-1 palmitate chain from phospholipid to lipopolysaccharide in Gram-negative bacteria. A recent x-ray crystallographic study established that the sn-1 palmitate binds within a long cavity at the center of the PagP beta barrel. The high mobility required to permit substrate entry into the central core of the barrel contrasts with the need to assemble a well defined …