Structure and Function of Piezophilic Hyperthermophilic Pyrococcus yayanosii pApase.

Zheng Jin,Xiang Xiao,Gangshun Yi,Qisheng Wang,Xuegong Li,Weiwei Wang,Feng Yu,Huan Zhou,Xipeng Liu

doi:10.3390/ijms22137159

Abstract

3’-Phosphoadenosine 5’-monophosphate (pAp) is a byproduct of sulfate assimilation and coenzyme A metabolism. pAp can inhibit the activity of 3′-phosphoadenosine 5′-phosphosulfate (PAPS) reductase and sulfotransferase and regulate gene expression under stress conditions by inhibiting XRN family of exoribonucleases. In metazoans, plants, yeast, and some bacteria, pAp can be converted into 5’-adenosine monophosphate (AMP) and inorganic phosphate by CysQ. In some bacteria and archaea, nanoRNases (Nrn) from the Asp-His-His (DHH) phosphoesterase superfamily are responsible for recycling pAp. In addition, histidinol phosphatase from the amidohydrolase superfamily can hydrolyze pAp. The bacterial enzymes for pAp turnover and their catalysis mechanism have been well studied, but these processes remain unclear in archaea. Pyrococcus yayanosii, an obligate piezophilic hyperthermophilic archaea, encodes a DHH family pApase homolog (PyapApase). Biochemical characterization showed that PyapApase can efficiently convert pAp into AMP and phosphate. The resolved crystal structure of apo-PyapApase is similar to that of bacterial nanoRNaseA (NrnA), but they are slightly different in the α-helix linker connecting the DHH and Asp-His-His associated 1 (DHHA1) domains. The longer α-helix of PyapApase leads to a narrower substrate-binding cleft between the DHH and DHHA1 domains than what is observed in bacterial NrnA. Through mutation analysis of conserved amino acid residues involved in coordinating metal ion and binding substrate pAp, it was confirmed that PyapApase has an ion coordination pattern similar to that of NrnA and slightly different substrate binding patterns. The results provide combined structural and functional insight into the enzymatic turnover of pAp, implying the potential function of sulfate assimilation in hyperthermophilic cells.

Highlights

Sulfate assimilation is an important biological process that exists in metazoans, plants, fungi, and some prokaryotes [1,2,3,4]
phosphoadenosine -phosphosulfate (PAPS) is used as a sulfate donor by PAPS reductase to generate sulfite or by sulfotransferase to produce sulfonated molecules and proteins [5,6,7,8], accompanied by the generation of 3 -phosphoadenosine 5 -monophosphate
As a byproduct in PAPS metabolism, phosphoadenosine -monophosphate (pAp) plays important roles in cell functions. It can inhibit the activities of PAPS reductase and sulfotransferase in sulfate assimilation [9] and the activity of oligoribonuclease (Orn) during oligo RNA degradation [10], and regulate gene expression by inhibiting the XRN family of exoribonucleases in plants [11,12]

Summary

Introduction

Sulfate assimilation is an important biological process that exists in metazoans, plants, fungi, and some prokaryotes [1,2,3,4] It can produce sulfur-containing amino acids, derivatives of sulfur-containing amino acids, and sulfonated products through 3 -phosphoadenosine. As a byproduct in PAPS metabolism, pAp plays important roles in cell functions It can inhibit the activities of PAPS reductase and sulfotransferase in sulfate assimilation [9] and the activity of oligoribonuclease (Orn) during oligo RNA degradation [10], and regulate gene expression by inhibiting the XRN family of exoribonucleases in plants [11,12]. PAp is hydrolyzed by specialized phosphoesterases to generate 5’-adenosine monophosphate (AMP) and inorganic phosphate (Pi) These specialized phosphoesterases include CysQ from the FIG superfamily (fructose-1,6-bisphosphatase/inositol monophosphatase/glpX), nanoRNases (Nrn) from the Asp-His-His (DHH) phosphoesterase superfamily, and histidinol phosphatase from the amidohydrolase superfamily. Cv1693, a histidinol phosphatase from Chromobacterium violaceum, belongs to the amidohydrolase superfamily and can hydrolyze pAp [18]

Methods

Results

Conclusion