[1][2] Arginine fingers are often found in the protein superfamily of AAA+ ATPases, GTPases, and dUTPases, where they assist in the catalysis of the gamma phosphate or gamma and beta phosphates from ATP or GTP, which creates a release of energy which can be used to perform cellular work.
[7][8] Generally, the role of the arginine finger in catalysis is to function in transition state stabilization to allow water to perform a nucleophilic attack to cleave off a number of phosphate groups.
[9][7] Additionally, arginine fingers may be attached to different subunits or other proteins in a multiprotein complex.
[1] For example, in some trimeric dUTPases, such as those of M. tuberculosis, arginine fingers at the 64th and 140th residue can work with magnesium to cleave dUTP into dUMP and a pyrophosphate.
[1][11] The underlying mechanism of action for this is a nucleophilic attack; the positively charged magnesium ion (Mg2+) pulls on an oxygen of the beta and gamma phosphates to allow water to hydrolyze the bond between the beta and alpha phosphates.
[12][6] Ras is a GTPase which functions in signal transduction to regulate cell growth and division.
[16] Mutations affecting the arginine fingers of Ras lead to trouble catalyzing GTP by factors of around two to five orders of magnitude.
[18][8] One of these helicases, the Bloom syndrome protein, contains an arginine finger which assists in its hydrolysis of ATP.