Phosphate-independent expression of the carbon-phosphorus lyase activity of Escherichia coli

1998 ◽  
Vol 49 (5) ◽  
pp. 573-578 ◽  
Author(s):  
G. M. Yakovleva ◽  
S.-K. Kim ◽  
B. L. Wanner
1999 ◽  
Vol 181 (2) ◽  
pp. 389-395 ◽  
Author(s):  
George F. Parker ◽  
Timothy P. Higgins ◽  
Timothy Hawkes ◽  
Robert L. Robson

ABSTRACT In Escherichia coli, the phn operon encodes proteins responsible for the uptake and breakdown of phosphonates. The C-P (carbon-phosphorus) lyase enzyme encoded by this operon which catalyzes the cleavage of C-P bonds in phosphonates has been recalcitrant to biochemical characterization. To advance the understanding of this enzyme, we have cloned DNA fromRhizobium (Sinorhizobium) melilotithat contains homologues of the E. coli phnG, -H, -I, -J, and -Kgenes. We demonstrated by insertional mutagenesis that the operon from which this DNA is derived encodes the R. meliloti C-P lyase. Furthermore, the phenotype of this phn mutant shows that the C-P lyase has a broad substrate specificity and that the organism has another enzyme that degrades aminoethylphosphonate. A comparison of the R. meliloti and E. coli phngenes and their predicted products gave new information about C-P lyase. The putative R. meliloti PhnG, PhnH, and PhnK proteins were overexpressed and used to make polyclonal antibodies. Proteins of the correct molecular weight that react with these antibodies are expressed by R. meliloti grown with phosphonates as sole phosphorus sources. This is the first in vivo demonstration of the existence of these hitherto hypothetical Phn proteins.


2007 ◽  
Vol 43 (4) ◽  
pp. 394-398 ◽  
Author(s):  
S. V. Kononova ◽  
S. M. Trutko ◽  
K. S. Laurinavichus

2009 ◽  
Vol 192 (1) ◽  
pp. 370-374 ◽  
Author(s):  
Bjarne Hove-Jensen ◽  
Tina J. Rosenkrantz ◽  
David L. Zechel ◽  
Martin Willemoës

ABSTRACT The catabolism of phosphonic acids occurs in Escherichia coli by the carbon-phosphorus lyase pathway, which is governed by the 14-cistron phn operon. Here, several compounds are shown to accumulate in strains of E. coli with genetic blocks in various phn cistrons when the strains are fed with phosphonate.


2010 ◽  
Vol 76 (9) ◽  
pp. 2729-2739 ◽  
Author(s):  
Avijit Biswas ◽  
Yasmin M. Vasquez ◽  
Tierna M. Dragomani ◽  
Monica L. Kronfel ◽  
Shervonda R. Williams ◽  
...  

ABSTRACT Phycobiliproteins are water-soluble, light-harvesting proteins that are highly fluorescent due to linear tetrapyrrole chromophores, which makes them valuable as probes. Enzymes called bilin lyases usually attach these bilin chromophores to specific cysteine residues within the alpha and beta subunits via thioether linkages. A multiplasmid coexpression system was used to recreate the biosynthetic pathway for phycobiliproteins from the cyanobacterium Synechococcus sp. strain PCC 7002 in Escherichia coli. This system efficiently produced chromophorylated allophycocyanin (ApcA/ApcB) and α-phycocyanin with holoprotein yields ranging from 3 to 12 mg liter−1 of culture. This heterologous expression system was used to demonstrate that the CpcS-I and CpcU proteins are both required to attach phycocyanobilin (PCB) to allophycocyanin subunits ApcD (αAP-B) and ApcF (β18). The N-terminal, allophycocyanin-like domain of ApcE (LCM 99) was produced in soluble form and was shown to have intrinsic bilin lyase activity. Lastly, this in vivo system was used to evaluate the efficiency of the bilin lyases for production of β-phycocyanin.


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