Physiological Role of phnP-specified Phosphoribosyl Cyclic Phosphodiesterase in Catabolism of Organophosphonic Acids by the Carbon−Phosphorus Lyase Pathway

TY - JOUR

T1 - Physiological Role of phnP-specified Phosphoribosyl Cyclic Phosphodiesterase in Catabolism of Organophosphonic Acids by the Carbon−Phosphorus Lyase Pathway

AU - Hove-Jensen, Bjarne

AU - McSorley, Fern R.

AU - Zechel, David L.

PY - 2011/3/16

Y1 - 2011/3/16

N2 - In Escherichia coli, internalization and catabolism of organophosphonicacids are governed by the 14-cistron phnCDEFGHIJKLMNOP operon. The phnP gene product was previously shown to encode a phosphodiesterase with unusual specificity toward ribonucleoside 2′,3′-cyclic phosphates. Furthermore, phnP displays shared synteny with phnN across bacterial phn operons. Here the role of PhnP was examined by 31P NMR spectrometry on the culture supernatants of E. coliphn mutants grown in the presence of alkylphosphonic acid or phosphite. The addition of any of these alkylphosphonic acids or phosphite resulted in the accumulation of α-d-ribosyl 1,2-cyclic phosphate and α-d-ribosyl 1-alkylphosphonate in a phnP mutant strain. Additionally, α-d-ribosyl 1-ethylphosphonate was observed to accumulate in a phnJ mutant strain when it was fed ethylphosphonic acid. Purified PhnP was shown to regiospecifically convert α-d-ribosyl 1,2-cyclic phosphate to α-d-ribosyl 1-phosphate. Radiolabeling studies revealed that 5-phospho-α-d-ribosyl 1,2-cyclic phosphate also accumulates in a phnP mutant. This compound was synthesized and shown to be regiospecifically converted by PhnP to α-d-ribosyl 1,5-bisphosphate. It is also shown that organophosphonate catabolism is dependent on the synthesis of 5-phospho-α-d-ribosyl 1-diphosphate, suggesting that this phosphoribosyl donor is used to initiate the carbon-phosphorus (CP) lyase pathway. The results show that 5-phospho-α-d-ribosyl 1,2-cyclic phosphate is an intermediate of organophosphonic acid catabolism, and it is proposed that this compound derives from C-P bond cleavage of 5-phospho-α-d-ribosyl 1-alkylphosphonates by CP lyase.

AB - In Escherichia coli, internalization and catabolism of organophosphonicacids are governed by the 14-cistron phnCDEFGHIJKLMNOP operon. The phnP gene product was previously shown to encode a phosphodiesterase with unusual specificity toward ribonucleoside 2′,3′-cyclic phosphates. Furthermore, phnP displays shared synteny with phnN across bacterial phn operons. Here the role of PhnP was examined by 31P NMR spectrometry on the culture supernatants of E. coliphn mutants grown in the presence of alkylphosphonic acid or phosphite. The addition of any of these alkylphosphonic acids or phosphite resulted in the accumulation of α-d-ribosyl 1,2-cyclic phosphate and α-d-ribosyl 1-alkylphosphonate in a phnP mutant strain. Additionally, α-d-ribosyl 1-ethylphosphonate was observed to accumulate in a phnJ mutant strain when it was fed ethylphosphonic acid. Purified PhnP was shown to regiospecifically convert α-d-ribosyl 1,2-cyclic phosphate to α-d-ribosyl 1-phosphate. Radiolabeling studies revealed that 5-phospho-α-d-ribosyl 1,2-cyclic phosphate also accumulates in a phnP mutant. This compound was synthesized and shown to be regiospecifically converted by PhnP to α-d-ribosyl 1,5-bisphosphate. It is also shown that organophosphonate catabolism is dependent on the synthesis of 5-phospho-α-d-ribosyl 1-diphosphate, suggesting that this phosphoribosyl donor is used to initiate the carbon-phosphorus (CP) lyase pathway. The results show that 5-phospho-α-d-ribosyl 1,2-cyclic phosphate is an intermediate of organophosphonic acid catabolism, and it is proposed that this compound derives from C-P bond cleavage of 5-phospho-α-d-ribosyl 1-alkylphosphonates by CP lyase.

U2 - 10.1021/ja1102713

DO - 10.1021/ja1102713

M3 - Journal article

C2 - 21341651

SN - 0002-7863

VL - 133

SP - 3617

EP - 3624

JO - Journal of the American Chemical Society

JF - Journal of the American Chemical Society

IS - 10

ER -