The amount of information available about membrane proteins is now too large for any one person to be familiar with anything but a small part of the primary literature. "Biomembranes" which concentrates on molecular aspects of biological membranes is therefore a timely publication. The hope of the editors is that when complete, these volumes will provide a convenient introduction to the study of a wide range of membrane functions. Volume 5 covers an important group of membrane proteins, the ATPases. The P-type ATPases couple the hydrolysis of ATP to the movement of ions across a membrane and are characterized by the formulation of a phosphorylated intermediate. Included are the plasma membrane and muscle sarcoplasmic reticulum Ca2+ATPases, the gastric (H+-K+)-ATPase, the plasma membrane H+-ATPase of fungi, and plants, the Mg2+transport ATPases of salmonella typhimurium and the K+-ATPase of escherichia coli, KdpB. The other important classes of ATPase in eukaryotic systems are the vacuolar H+-ATPases, and the F0F1 ATP synthase, and in bacteria, the anion-translocating ATPases responsible for resistance to antimonials and arsenicals, and the (Na++Mg2+)-ATPase of acholeplasma. Finally, eukaryotic systems contain a variety of ectonucleotidases. This book explores structure-function relationships for these membrane-bound ATPases. Written by leading workers active in this area of research, this volume will be of interest to a diverse audience of biologists and scientists inside and outside the area of molecular biology.