microbiology, Vol 141, 147-154, Copyright © 1995 by Society for General Microbiology

ARTICLES

Cloning and characterization of the NapA acid phosphatase/phosphotransferase of Morganella morganii: identification of a new family of bacterial acid-phosphatase-encoding genes

MC Thaller, G Lombardi, F Berlutti, S Schippa and GM Rossolini
Istituto di Microbiologia, Universita La Sapienza, Rome, Italy.

The gene encoding a minor phosphate-irrepressible acid phosphatase (named NapA) of Morganella morganii was cloned and sequenced, and its product characterized. NapA is a secreted acid phosphatase composed of four 27 kDa polypeptide subunits. The enzyme is active on several organic phosphate monoesters but not on diesters, and is also endowed with transphosphorylating activity from organic phosphoric acid esters to nucleosides and other compounds with free hydroxyl groups. Its activity is inhibited by EDTA, inorganic phosphate, nucleosides and Ca2+, but not by fluoride or tartrate, and is enhanced by Mg2+, Co2+ and Zn2+. At the sequence level, the NapA enzyme did not show similarities to any other sequenced bacterial phosphatases. However, a search for homologous genes in sequence databases allowed identification of two open reading frames located within sequenced regions of the Escherichia coli and Proteus mirabilis genomes respectively, encoding proteins of unknown function which are highly homologous to the Morganella enzyme. Moreover, the properties of the NapA enzyme are very similar to those reported for the periplasmic nonspecific acid phosphatase II of Salmonella typhimurium (for which no sequence data are available). These data point to the existence of a new family of bacterial acid phosphatases, which we propose designating class B bacterial acid phosphatases.

This article has been cited by other articles:

				B. Lei, S. Mackie, S. Lukomski, and J. M. Musser Identification and Immunogenicity of Group A Streptococcus Culture Supernatant Proteins Infect. Immun., December 1, 2000; 68(12): 6807 - 6818. [Abstract] [Full Text] [PDF]

				H. Malke Cytoplasmic Membrane Lipoprotein LppC of Streptococcus equisimilis Functions as an Acid Phosphatase Appl. Envir. Microbiol., July 1, 1998; 64(7): 2439 - 2442. [Abstract] [Full Text]