Keratin, type I cuticular Ha3-II is a

protein Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, respo ...

that in humans is encoded by the ''KRT33B''

gene In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a ba ...

. The protein encoded by this gene is a member of the

keratin Keratin () is one of a family of structural fibrous proteins also known as ''scleroproteins''. Alpha-keratin (α-keratin) is a type of keratin found in vertebrates. It is the key structural material making up scales, hair, nails, feathers, ho ...

gene family. It is one of the

type I hair keratin Hair keratin is a type of keratin found in hair and nail (anatomy), nails. There are two types of hair keratin: * the acidic ''type I hair keratin'' **KRT31, type I hair keratin 1, **KRT32, type I hair keratin 2, **KRT33A, type I hair keratin 3A ...

genes which are clustered in a region of chromosome 17q12-q21 and have the same direction of transcription. As a type I hair keratin, it is an acidic protein which heterodimerizes with

type II hair keratin Hair keratin is a type of keratin found in hair and nails. There are two types of hair keratin: * the acidic In computer science, ACID ( atomicity, consistency, isolation, durability) is a set of properties of database transactions intende ...

to form

hair Hair is a protein filament that grows from follicles found in the dermis. Hair is one of the defining characteristics of mammals. The human body, apart from areas of glabrous skin, is covered in follicles which produce thick terminal and f ...

and nails. There are two isoforms of this protein, encoded by two separate genes, KRTHA3A and KRTHA3B.

References

Further reading