heterotetramerer

A heterotetramerer is a protein complex composed of four subunits, where at least two different types of subunits are present. The term "hetero" signifies difference, indicating that the subunits are not all identical. "Tetra" refers to the total number of subunits, which is four. Therefore, a heterotetramerer is a quaternary structure protein made up of four polypeptide chains, with the composition not being four identical chains. For example, a heterotetramerer could consist of two subunits of type A and two subunits of type B, or one subunit of type A, one of type B, and two of type C, as long as there is more than one distinct subunit type. The specific arrangement and interaction of these different subunits are crucial for the protein's overall function. Many enzymes and regulatory proteins exist as heterotetramers, with the diverse subunits contributing distinct functional or structural roles to the assembled complex. This arrangement allows for complex regulatory mechanisms and a broader range of interactions compared to homooligomeric proteins, which are composed of identical subunits.