alexa A protein tyrosine phosphatase-like inositol polyphosphatase from Selenomonas ruminantium subsp. lactilytica has specificity for the 5-phosphate of myo-inositol hexakisphosphate.
Genetics

Genetics

Advancements in Genetic Engineering

Author(s): Puhl AA, Greiner R, Selinger LB

Abstract Share this page

Abstract Although it is becoming well known that myo-inositol polyphosphates and the enzymes involved in their metabolism play a critical role in eukaryotic systems, little is understood of their significance in prokaryotic systems. A novel protein tyrosine phosphatase (PTP)-like inositol polyphosphatase (IPPase) gene has been cloned from Selenomonas ruminantium subsp. lactilytica (phyAsrl). The deduced amino acid sequence of PhyAsrl is most similar to a PTP-like IPPase from the anaerobic bacterium S. ruminantium (35\% identity), but also shows similarity (19-30\% identity) to various other putative prokaryotic PTPs. Recombinant PhyAsrl could dephosphorylate myo-inositol hexakisphosphate (Ins P(6)) in vitro, and maximal activity was displayed at an ionic strength of 200 mM, a pH of 4.5, and a temperature of 55 degrees C. In order to elucidate its substrate specificity and pathway of Ins P(6) dephosphorylation, a combination of kinetic and high-performance ion-pair chromatography studies were conducted. The data indicated that PhyAsrl has a general specificity for polyphosphorylated myo-inositol substrates, but can also dephosphorylate molecules containing high energy pyrophosphate bonds in vitro. PhyAsrl is unique from other microbial IPPases in that it preferentially cleaves the 5-phosphate position of Ins P(6). Furthermore, it can produce Ins(2)P via a highly unique and ordered pathway of sequential dephosphorylation: Ins P(6), Ins(1,2,3,4,6)P(5), D-Ins(1,2,3,6)P(4), Ins(1,2,3)P(3), and D/L-Ins(1,2)P(2). Finally, reverse transcription PCR was used to determine that phyAsrl is constitutively expressed, and together with bioinformatic analysis, was used to gain an understanding of its physiological significance. This article was published in Int J Biochem Cell Biol and referenced in Advancements in Genetic Engineering

Relevant Expert PPTs

Relevant Speaker PPTs

Recommended Conferences

  • International Conference on Epigenetics 2017
    November 13-15, 2017 Frankfurt, Germany
  • International Conference on Genetic Counseling and Genomic Medicine
    February 12-13, 2018 Madrid, Spain

Relevant Topics

Peer Reviewed Journals
 
Make the best use of Scientific Research and information from our 700 + peer reviewed, Open Access Journals
International Conferences 2017-18
 
Meet Inspiring Speakers and Experts at our 3000+ Global Annual Meetings

Contact Us

 
© 2008-2017 OMICS International - Open Access Publisher. Best viewed in Mozilla Firefox | Google Chrome | Above IE 7.0 version
adwords