Inositol polyphosphate kinase (IPK) is a family of enzymes that have a similar 3-dimensional structure. All members of the family catalyze the transfer of
phosphate group
In chemistry, a phosphate is an anion, salt, functional group or ester derived from a phosphoric acid. It most commonly means orthophosphate, a derivative of orthophosphoric acid .
The phosphate or orthophosphate ion is derived from phosphor ...
s from
ATP to various inositol phosphates. Members of the family include
inositol-polyphosphate multikinase
Inositol-polyphosphate multikinase (, ''IpK2'', ''IP3/IP4 6-/3-kinase'', ''IP3/IP4 dual-specificity 6-/3-kinase'', ''IpmK'', ''ArgRIII'', ''AtIpk2alpha'', ''AtIpk2beta'', ''inositol polyphosphate 6-/3-/5-kinase'') is an enzyme with systematic name ...
s,
inositol-hexakisphosphate kinases,
inositol-trisphosphate 3-kinase
Inositol (1,4,5) trisphosphate 3-kinase (), abbreviated here as ITP3K, is an enzyme that facilitates a phospho-group transfer from adenosine triphosphate to 1D-myo-inositol 1,4,5-trisphosphate. This enzyme belongs to the family of transferases, s ...
s, and
inositol-pentakisphosphate 2-kinase, which is more distantly related to the others
[ ]
The discovery of the IPK family occurred in 1999, when a combination of
biochemistry
Biochemistry or biological chemistry is the study of chemical processes within and relating to living organisms. A sub-discipline of both chemistry and biology, biochemistry may be divided into three fields: structural biology, enzymology and ...
,
sequence analysis
In bioinformatics, sequence analysis is the process of subjecting a DNA, RNA or peptide sequence to any of a wide range of analytical methods to understand its features, function, structure, or evolution. Methodologies used include sequence alignm ...
, and
genetics
Genetics is the study of genes, genetic variation, and heredity in organisms.Hartl D, Jones E (2005) It is an important branch in biology because heredity is vital to organisms' evolution. Gregor Mendel, a Moravian Augustinian friar wor ...
led to the classification of a family of inositol polyphosphate kinases.
[ ][ ] In 2005, the first crystal structures of an IPK family protein were published for
ITPKA
Inositol-trisphosphate 3-kinase A is an enzyme that in humans is encoded by the ''ITPKA'' gene.
Structure
ITPKA is one of three inositol-trisphosphate 3-kinase (ITP3K) genes in humans. ITP3K proteins regulate inositol phosphate metabolism by p ...
.
[ ][ ]
Subsequently, structures of the inositol polyphosphate multikinase and various IP6 kinases have expanded our structural understanding for how each enzyme catalyzes its specific reaction(s).
References
{{Reflist
Transferases