This is the N-terminal domain from PI3-kinase catalytic subunit gamma (PIK3CG, also known as p110 catalytic subunit gamma) which contains the adaptor-binding domain (ABD). This is a globular domain with an alpha/beta sandwich topology, common to all catalytic subunits of PIK3s, and it is similar to ubiquitin-like domains. This domain interacts with the regulatory subunit of the p101 type [1,2,3].

1: Crystal structure and functional analysis of Ras binding to its effector phosphoinositide 3-kinase gamma. Pacold ME, Suire S, Perisic O, Lara-Gonzalez S, Davis CT, Walker EH, Hawkins PT, Stephens L, Eccleston JF, Williams RL; Cell. 2000;103:931-943. PMID:11136978

2: Mechanism of two classes of cancer mutations in the phosphoinositide 3-kinase catalytic subunit. Miled N, Yan Y, Hon WC, Perisic O, Zvelebil M, Inbar Y, Schneidman-Duhovny D, Wolfson HJ, Backer JM, Williams RL; Science. 2007;317:239-242. PMID:17626883

3: The p110 delta structure: mechanisms for selectivity and potency of new PI(3)K inhibitors. Berndt A, Miller S, Williams O, Le DD, Houseman BT, Pacold JI, Gorrec F, Hon WC, Liu Y, Rommel C, Gaillard P, Ruckle T, Schwarz MK, Shokat KM, Shaw JP, Williams RL; Nat Chem Biol. 2010;6:117-124. PMID:20081827