  In view of the notorious complexity of protein--protein interactions,
simplified models of proteins treated as patchy particles offer a promising
strategy to obtain insight into the mechanism of crystallization. Here we
report liquid--liquid phase separation (LLPS) with a highly asymmetric
coexistence region in a computational model of rubredoxin with real molecular
shape. The coexistence region terminates in both an upper (UCST) and a lower
(LCST) critical solution temperature, and the complex molecular shape explains
the closed-loop behavior of the LLPS.
