The biochemical properties and phylogenies of phosphofructokinases from extremophiles

Abstract

The enzyme phosphofructokinase (PFK) is a defining activity of the highly conserved glycolytic pathway, and is present in the domains Bacteria, Eukarya, and Archaea. PFK subtypes are now known that utilize either ATP, ADP, or pyrophosphate as the primary phosphoryl donor and share the ability to catalyze the transfer of phosphate to the 1-position of fructose-6-phosphate. Because of the crucial position in the glycolytic pathway of PFKs, their biochemical characteristics and phylogenies may play a significant role in elucidating the origins of glycolysis and, indeed, of metabolism itself. Despite the shared ability to phosphorylate fructose-6-phosphate, PFKs that have been characterized to date now fall into three sequence families: the PFKA family, consisting of the well-known higher eukaryotic ATP-dependent PFKs together with their ATP- and pyrophosphate-dependent bacterial cousins (including the crenarchaeal pyrophosphate-dependent PFK of Thermoprotetus tenax) and plant pyrophosphate-dependent phosphofructokinases; the PFKB family, exemplified by the minor ATP-dependent PFK activity of Escherichia coli (PFK 2), but which also includes at least one crenarchaeal enzyme in Aeropyrum pernix; and the tentatively named PFKC family, which contains the unique ADP-dependent PFKs from the euryarchaeal genera of Pyrococcus and Thermococcus, which are indicated by sequence analysis to be present also in the methanogenic species Methanococcus jannaschii and Methanosarcina mazei.

Plastidial Thioredoxin z Interacts with Two Fructokinase-Like Proteins in a Thiol-Dependent Manner: Evidence for an Essential Role in Chloroplast Development in Arabidopsis and Nicotiana benthamiana

“…By contrast, all attempts to detect enzymatic activity of the two FLNs identified in our studies so far failed. The pfkB family of sugar kinases comprises proteins with diverse ATP-dependent sugar phosphorylation specificities, such as for ribose, adenosine, or fructose, among others (Bork et al, 1993;Ronimus and Morgan, 2001). Although there is a possibility that both FLNs have an enzymatic activity other than phosphorylating fructose, we currently favor the hypothesis that during evolution both proteins acquired a new function in plastid transcription.…”

Carbohydrate Metabolism in Archaea: Current Insights into Unusual Enzymes and Pathways and Their Regulation

“…These classical PFKs from Bacteria and Eukarya belong to the phosphofructokinase A (PFK-A) family (98). Bacterial PFKs from the PFK-A family are usually tetramers composed of single 35-kDa subunits (99,100). Each subunit comprises two domains, a large and a smaller 3-layered ␣␤␣ sandwich domain (101).…”

Proteomic Analysis of a Sea-Ice Diatom: Salinity Acclimation Provides New Insight into the Dimethylsulfoniopropionate Production Pathway

“…Because the latter two proteins were identified in mixed protein spots (with another protein contributing a large portion of the spectrum counts), these data must be interpreted cautiously given the methodological limitations. However, utilization of pyrophosphatedependent phosphofructo-1-kinase is an intriguing acclimation mechanism to replace the more typical ATP-dependent form, thereby conserving ATP for other metabolic processes (Ronimus and Morgan, 2001). Glyceraldehyde-3-P dehydrogenase is interesting because it is key to generating the energetic cofactor NADPH (Gao and Loescher, 2000) utilized by several of the other enzymes elevated in response to hypersalinity, including the second step in DMSP synthesis.…”