Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 1993 Jan 5;268(1):633-9.

An exopolyphosphatase of Escherichia coli. The enzyme and its ppx gene in a polyphosphate operon

M Akiyama  1 , E Crooke, A Kornberg
Affiliations
  • PMID: 8380170
Free article

An exopolyphosphatase of Escherichia coli. The enzyme and its ppx gene in a polyphosphate operon

M Akiyama et al. J Biol Chem. .
Free article

Abstract

A gene, ppx, that encodes a novel exopolyphosphatase of 513 amino acids (58,133 Da) was found downstream of the gene for polyphosphate kinase, ppk. Transcription of the ppx gene depends on the ppk promoters, indicating a polyphosphate (polyP) operon of ppk and ppx. Exopolyphosphatase, purified to homogeneity from overproducing cells, is judged to be a dimer of 58-kDa subunits. Orthophosphate is released processively from the ends of polyP approximately 500 residues long, but chains of approximately 15 residues compete poorly with polyP as substrate; ATP is not a substrate. Mg2+ (1 mM) and a high concentration of K+ (175 mM) support optimal activity.

PubMed Disclaimer

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

Publication types

MeSH terms

Associated data

LinkOut - more resources