Matrix metalloproteinases (MMPs) are zinc-containing endopeptidases. They degrade proteins by cleavage of peptide bonds. More than twenty MMPs have been identified and are separated into six groups based on their structure and substrate specificity (collagenases, gelatinases, membrane type [MT-MMP], stromelysins, matrilysins, and others).
Confidence votes 164. Alleles are the different forms of a gene. Alleles are corresponding pairs of genes located at specific positions in the chromosomes. Together, alleles determine the genotype. Alleles which determine some aspect of the phenotype, the physical appearance of an organism, are said to be coding alleles.
These proteins are formed as a result of genes carried on chromosomes. In genetics genes are represented by letters. There are usually 2 different types of the same gene; one is dominant and one is recessive. An example of this is: T is a gene for tall and t is a gene for short. The two versions of the same gene are called alleles. The two alleles are formed at the same position, or locus, on the chromosome.