Homology modeling, conjointly called comparative modeling of macromolecule, refers to constructing associate atomic-resolution model of the "target" macromolecule from its aminoalkanoic acid sequence associated an experimental three-dimensional structure of a connected homologous macromolecule. similarity modeling depends on the identification of 1 or a lot of notable macromolecule structures doubtless to agree the structure of the question sequence, associated on the assembly of an alignment that maps residues within the question sequence to residues within the model sequence. similarity modeling is that the most correct machine technique to make reliable structural models and is often employed in several biological applications. similarity modeling predicts the 3D structure of a question  macromolecule through the sequence alignment of model proteins. Evolutionarily connected macromolecules have similar sequences and present homologous proteins have similar protein structure. it's been shown that three-dimensional macromolecule structure is evolutionarily a lot of preserved than would be expected on the idea of sequence conservation alone. similarity modeling will manufacture high-quality structural models once the target and model square measure closely connected, that has impressed the formation of a genomics syndicate dedicated to the assembly of representative experimental structures for all categories of macromolecule folds.