G proteins are so-called because they bind the guanine nucleotides GDP and GTP. They are heterotrimers (i.e., made of three different subunits) associated with. the inner surface of the plasma membrane and. transmembrane receptors of hormones, etc. These are called G protein-coupled receptors (GPCRs).
Apply the metal paint to the mailbox in slow and even sections. Be sure to cover every inch of the metal mailbox including the door, hanging lip and the back. When this layer is dry remove the tape from the mailbox flag.
Create a rough surface on the sheet metal. Using high-grit sandpaper or steel wool, rub the surface of the sheet metal. This will allow the paint to adhere to the metal. Create a light, even texture on the surface and avoid making deep grooves in the metal. To remove stubborn rust spots, use a drill with a circular wire brush attachment.