Sulfotransferase 1A3/1A4 is an
enzyme
Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products. A ...
that in humans is encoded by the ''SULT1A3''
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 ...
.
Sulfotransferase enzymes catalyze the
sulfate conjugation of many
hormones
A hormone (from the Ancient Greek, Greek participle , "setting in motion") is a class of cell signaling, signaling molecules in multicellular organisms that are sent to distant organs by complex biological processes to regulate physiology and beh ...
,
neurotransmitters
A neurotransmitter is a signaling molecule secreted by a neuron to affect another cell across a synapse. The cell receiving the signal, any main body part or target cell, may be another neuron, but could also be a gland or muscle cell.
Neur ...
, drugs, and
xenobiotic
A xenobiotic is a chemical substance found within an organism that is not naturally produced or expected to be present within the organism. It can also cover substances that are present in much higher concentrations than are usual. Natural compo ...
compounds. These
cytosolic
The cytosol, also known as cytoplasmic matrix or groundplasm, is one of the liquids found inside cells (intracellular fluid (ICF)). It is separated into compartments by membranes. For example, the mitochondrial matrix separates the mitochondrio ...
enzymes are different in their tissue distributions and substrate specificities. The
gene structure
Gene structure is the organisation of specialised sequence elements within a gene. Genes contain most of the information necessary for living cells to survive and reproduce. In most organisms, genes are made of DNA, where the particular DNA sequen ...
(number and length of
exons
An exon is any part of a gene that will form a part of the final mature RNA produced by that gene after introns have been removed by RNA splicing. The term ''exon'' refers to both the DNA sequence within a gene and to the corresponding sequence ...
) is similar among
family members
Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Ideall ...
. This gene encodes a
phenol
Phenol (also called carbolic acid) is an aromatic organic compound with the molecular formula . It is a white crystalline solid that is volatile. The molecule consists of a phenyl group () bonded to a hydroxy group (). Mildly acidic, it req ...
sulfotransferase with
thermolabile
Thermolabile refers to a substance which is subject to destruction, decomposition, or change in response to heat. This term is often used to describe biochemical substances.
For example, many bacterial exotoxins are thermolabile and can be eas ...
enzyme activity. Four sulfotransferase genes are located on the p arm of
chromosome 16
Chromosome 16 is one of the 23 pairs of chromosomes in humans. People normally have two copies of this chromosome. Chromosome 16 spans about 90 million base pair
A base pair (bp) is a fundamental unit of double-stranded nucleic acids consisting ...
; this gene and
SULT1A4 arose from a
segmental duplication
Low copy repeats (LCRs), also known as segmental duplications (SDs), are highly homologous sequence elements within the eukaryotic genome.
Repeats
The repeats, or duplications, are typically 10–300 kb in length, and bear greater than 95% sequ ...
. This gene is the most
centromeric
The centromere links a pair of sister chromatids together during cell division. This constricted region of chromosome connects the sister chromatids, creating a short arm (p) and a long arm (q) on the chromatids. During mitosis, spindle fibers ...
of the four sulfotransferase genes. Exons of this gene overlap with exons of a gene that encodes 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 ...
containing
GIY-YIG domains (GIYD1). Three alternatively spliced variants that encode the same protein have been described.
References
Further reading
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External links
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