Figure 6.

The pointed-end interface and the ATP binding pocket of Arp1p. (A) A stereoview of the pointed-end of an Arp1p pentamer. Ts^– and lethal residues are colored by mass-action rescue (red, rescued; blue, not rescued), and numbered by allele. arp1-104 (a rescued lethal allele) is highlighted in green. (B) Three of the ARP1 mutations line the ATP binding pocket of Arp1p. A stereoview is shown of the Arp1p ribbon structure. The ATP is represented in green. The backbone and side chains of arp1-33 are shown in yellow, arp1-101 in red, and arp1-113 in blue. A schematic representation of the filament consisting of boxes representing each monomer, each with a magenta inner face and teal outer face, serves as an orienting guide to the relative rotation of each filament.