Novel Activities of Glycolytic Enzymes in Bacillus subtilis

doi:10.1074/mcp.M800546-MCP200

Novel Activities of Glycolytic Enzymes in Bacillus subtilis

INTERACTIONS WITH ESSENTIAL PROTEINS INVOLVED IN mRNA PROCESSING*

From the ‡Department of General Microbiology, Georg-August-University Göttingen, Grisebachstrasse 8, D-37077 Göttingen, Germany and
¶Interfaculty Institute for Genetics and Functional Genomics, Ernst-Moritz-Arndt-University Greifswald, Friedrich-Ludwig-Jahnstrasse 15a, D-17487 Greifswald, Germany

‖ To whom correspondence should be addressed. Tel.: 49-551-393781; Fax: 49-551-393808; E-mail: jstuelk{at}gwdg.de.

Abstract

Glycolysis is one of the most important metabolic pathways in heterotrophic organisms. Several genes encoding glycolytic enzymes are essential in many bacteria even under conditions when neither glycolytic nor gluconeogenic activities are required. In this study, a screening for in vivo interaction partners of glycolytic enzymes of the soil bacterium Bacillus subtilis was used to provide a rationale for essentiality of glycolytic enzymes. Glycolytic enzymes proved to be in close contact with several other proteins, among them a high proportion of essential proteins. Among these essential interaction partners, other glycolytic enzymes were most prominent. Two-hybrid studies confirmed interactions of phosphofructokinase with phosphoglyceromutase and enolase. Such a complex of glycolytic enzymes might allow direct substrate channeling of glycolytic intermediates. Moreover we found associations of glycolytic enzymes with several proteins known or suspected to be involved in RNA processing and degradation. One of these proteins, Rny (YmdA), which has so far not been functionally characterized, is required for the processing of the mRNA of the glycolytic gapA operon. Two-hybrid analyses confirmed the interactions between the glycolytic enzymes phosphofructokinase and enolase and the enzymes involved in RNA processing, RNase J1, Rny, and polynucleotide phosphorylase. Moreover RNase J1 interacts with its homologue RNase J2. We suggest that this complex of mRNA processing and glycolytic enzymes is the B. subtilis equivalent of the RNA degradosome. Our findings suggest that the functional interaction of glycolytic enzymes with essential proteins may be the reason why they are indispensable.

Footnotes

↵§ Supported by the Fonds der Chemischen Industrie.
↵* This work was supported in part by grants from the Deutsche Forschungsgemeinschaft and the Federal Ministry of Education and Research Systems Biology of Microorganisms (SYSMO) network (Grants PtJ-BIO/0313978D and 0313978A) (to J. S. and U. V.).
↵ The on-line version of this article (available at http://www.mcponline.org) contains supplemental material.
↵² F. M. Rothe, M. Lehnik-Habrink, F. M. Commichau, and J. Stülke, unpublished results.
↵¹ The abbreviations used are:

GAPDH

glyceraldehyde-3-phosphate dehydrogenase

PGK

phosphoglycerate kinase

ENO

enolase

PFK

6-phosphofructokinase

FBA

fructose-1,6-bisphosphate aldolase

TPI

triose-phosphate isomerase

PGM

phosphoglycerate mutase

B2H

bacterial two-hybrid

SPINE

Strep-protein interaction experiment.
- Received December 1, 2008.
- Accepted January 30, 2009.