The CYP2W1 gene has nine exons resulting in an open reading frame of 1473bp.

At this point five different CYP2W1 transcripts have been described in different databases. In particular two transcripts have gained interest. The first variant, corresponding to the reference sequence, consists of nine exons and has a typical cytochrome P450 family 2 structure, containing conserved features etc. The second variant has only eight exons although the eight exon is longer in this transcript than in the nine-exon-transcript. The absence of a conserved cysteine indicates that this transcript can not result in a functional P450 enzyme (see figure below).

No pseudogene is known to date for CYP2W1.

CYP2W1 is a cytochrome P450 enzyme belonging to family 2. Other family 2 members are important for the metabolism of drugs and other xenobiotics. In mammals the P450 enzymes are membrane bound and mainly localized to the endoplasmic reticulum (ER) but also to the mitochondria.

All cytochrome P450 enzymes have a similar fold although their sequence identity can be very low. Structurally, P450 enzymes have a conserved core consisting of a four-helix bundle, including helices D, E, I and L, and the two helices J and K. In addition there are two sets of conserved beta-sheets containing five and two strands respectively. All P450 enzymes contain a heme group and one of the few conserved residues is a conserved cysteine serving as the fifth heme iron ligand. A structural similarity of mammalian P450 enzymes is the hydrophobic NH2-terminal part spanning the membrane and serving as membrane anchor.

CYP2W1 mRNA and/or protein are highly expressed in some cancer types including colon, adrenal gland, lung and gastric cancers. In addition high CYP2W1 expression has been detected in two human derived cell lines, Caco2-TC7 and HepG2. HepG2 is the cell line where CYP2W1 was first identified, however the expression levels in Caco2-TC7 exceeds the levels in HepG2 cells significantly. Some scientists have also reported CYP2W1 mRNA expression in various adult human tissues as well as in keratinocytes and MCF10A cells, however so far no protein has been identified in these tissues/cells, which might be an indication of low expression levels.
For non-human tissues high CYP2W1 mRNA expression levels are found in whole mouse embryo and in rat fetal colon. The expression in fetal rat colon increased by fetal age, whereas the opposite was seen in adult rat colon where the expression levels decreased again after birth.

Cytochrome P450 family 2 members are usually located in the ER membrane, however CYP2W1 have been detected both in microsomes (i.e. ER) and in mitochondria.

Cytochrome P450 enzymes are monooxidases and as mentioned other family 2 enzymes are involved in the metabolism of many drugs. The knowledge about CYP2W1 substrates are today limited. The substrates identified are arachidonic acid, benzfetamine and indole. In addition, CYP2W1 has been reported to activate a number of procarcinogens, e.g. PAHs, aflatoxin B1, sterigmatocystin etc. (for a more detailed list see Wu et al., 2006).
Based on the high CYP2W1 expression in fetal rat colon and mouse embryo it is possible that CYP2W1 has some yet unknown function during embryogenesis/differentiation.

- CYP2W1 (Pan troglodytes)
- Cyp2w1 (Mus musculus)
- Cyp2w1 (Rattus norvegicus)
Denoted as similar to CYP2W1:
- LOC416454 (Gallus gallus)
- LOC491601 (Canis lupus familiaris)

Several SNPs have been detected in the CYP2W1 gene, both synonymous and non-synonymous. For an updated overview of CYP2W1 polymorphisms and CYP2W1 alleles see http://www.cypalleles.ki.se/cyp2w1.htm.