GRAM domain-containing 2B protein (GRAMD2B; formerly GRAMD3), also known as NS3TP2 and HCV NS3-transactivated protein 2 is a

protein Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residue (biochemistry), residues. Proteins perform a vast array of functions within organisms, including Enzyme catalysis, catalysing metab ...

encoded by the GRAMD2B

gene In biology, the word gene has two meanings. The Mendelian gene is a basic unit of heredity. The molecular gene is a sequence of nucleotides in DNA that is transcribed to produce a functional RNA. There are two types of molecular genes: protei ...

. GRAMD2B has four

paralogs Sequence homology is the biological homology between DNA, RNA, or protein sequences, defined in terms of shared ancestry in the evolutionary history of life. Two segments of DNA can have shared ancestry because of three phenomena: either a speci ...

: GRAMD1A,

GRAMD1B GRAM domain containing 1B, also known as GRAMD1B, Aster-B and KIAA1201, is a cholesterol transport protein that is encoded by the ''GRAMD1B'' gene. It contains a Transmembrane protein, transmembrane region and two Protein domain, domains of know ...

, GRAMD1C and GRAMD2A. These proteins are mammalian representatives of the

yeast Yeasts are eukaryotic, single-celled microorganisms classified as members of the fungus kingdom (biology), kingdom. The first yeast originated hundreds of millions of years ago, and at least 1,500 species are currently recognized. They are est ...

lipid Lipids are a broad group of organic compounds which include fats, waxes, sterols, fat-soluble vitamins (such as vitamins A, D, E and K), monoglycerides, diglycerides, phospholipids, and others. The functions of lipids include storing ...

transfer proteins anchored at a membrane contact site (LAM) family. GRAMD2B consists of a

GRAM domain The GRAM domain is found in glucosyltransferases, myotubularins and other membrane-associated proteins. The structure of the GRAM domain is similar to that found in PH domains. Proteins containing GRAM domains are found in all eukaryotes and b ...

and a

transmembrane domain A transmembrane domain (TMD, TM domain) is a membrane-spanning protein domain. TMDs may consist of one or several alpha-helices or a transmembrane beta barrel. Because the interior of the lipid bilayer is hydrophobic, the amino acid residues in ...

anchoring it to the

endoplasmic reticulum The endoplasmic reticulum (ER) is a part of a transportation system of the eukaryote, eukaryotic cell, and has many other important functions such as protein folding. The word endoplasmic means "within the cytoplasm", and reticulum is Latin for ...

. Similar to GRAMD2A, GRAMD2B lacks the VASt domain found in LAM and GRAMD1 proteins. Its function has not yet been defined, but is likely similar to that of GRAMD2A.

References

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