Conserved network of proteins essential for bacterial viability

TY - JOUR

T1 - Conserved network of proteins essential for bacterial viability

A1 - Handford,Jennifer I.

A1 - Ize,Berengere

A1 - Buchanan,Grant

A1 - Butland,Gareth P.

A1 - Greenblatt,Jack

A1 - Emili,Andrew

A1 - Palmer,Tracy

AU - Handford,Jennifer I.

AU - Ize,Berengere

AU - Buchanan,Grant

AU - Butland,Gareth P.

AU - Greenblatt,Jack

AU - Emili,Andrew

AU - Palmer,Tracy

PY - 2009/8

Y1 - 2009/8

N2 - <p>The yjeE, yeaZ, and ygjD genes are highly conserved in the genomes of eubacteria, and ygjD orthologs are also found throughout the Archaea and eukaryotes. In this study, we have constructed conditional expression strains for each of these genes in the model organism Escherichia coli K12. We show that each gene is essential for the viability of E. coli under laboratory growth conditions. Growth of the conditional strains under nonpermissive conditions results in dramatic changes in cell ultrastructure. Deliberate repression of the expression of yeaZ results in cells with highly condensed nucleoids, while repression of yjeE and ygjD expression results in at least a proportion of very enlarged cells with an unusual peripheral distribution of DNA. Each of the three conditional expression strains can be complemented by multicopy clones harboring the rstA gene, which encodes a two-component-system response regulator, strongly suggesting that these proteins are involved in the same essential cellular pathway. The results of bacterial two-hybrid experiments show that YeaZ can interact with both YjeE and YgjD but that YgjD is the preferred interaction partner. The results of in vitro experiments indicate that YeaZ mediates the proteolysis of YgjD, suggesting that YeaZ and YjeE act as regulators to control the activity of this protein. Our results are consistent with these proteins forming a link between DNA metabolism and cell division.</p>

AB - <p>The yjeE, yeaZ, and ygjD genes are highly conserved in the genomes of eubacteria, and ygjD orthologs are also found throughout the Archaea and eukaryotes. In this study, we have constructed conditional expression strains for each of these genes in the model organism Escherichia coli K12. We show that each gene is essential for the viability of E. coli under laboratory growth conditions. Growth of the conditional strains under nonpermissive conditions results in dramatic changes in cell ultrastructure. Deliberate repression of the expression of yeaZ results in cells with highly condensed nucleoids, while repression of yjeE and ygjD expression results in at least a proportion of very enlarged cells with an unusual peripheral distribution of DNA. Each of the three conditional expression strains can be complemented by multicopy clones harboring the rstA gene, which encodes a two-component-system response regulator, strongly suggesting that these proteins are involved in the same essential cellular pathway. The results of bacterial two-hybrid experiments show that YeaZ can interact with both YjeE and YgjD but that YgjD is the preferred interaction partner. The results of in vitro experiments indicate that YeaZ mediates the proteolysis of YgjD, suggesting that YeaZ and YjeE act as regulators to control the activity of this protein. Our results are consistent with these proteins forming a link between DNA metabolism and cell division.</p>

KW - HAEMOLYTICA A1 GLYCOPROTEASE

KW - ESCHERICHIA-COLI

KW - ESSENTIAL GENES

KW - BACILLUS-SUBTILIS

KW - UNKNOWN FUNCTION

KW - TRANSLOCATION PATHWAY

KW - NUCLEOID CONDENSATION

KW - 2-HYBRID SYSTEM

KW - KEOPS COMPLEX

KW - IN-VITRO

U2 - 10.1128/JB.00136-09

DO - 10.1128/JB.00136-09

M1 - Article

JO - Journal of Bacteriology

JF - Journal of Bacteriology

SN - 0021-9193

IS - 15

VL - 191

SP - 4732

EP - 4749

ER -