# Unraveling the multiplicity of geranylgeranyl reductases in Archaea: potential roles in saturation of terpenoids

## TL;DR

This paper explores the role of geranylgeranyl reductases in Archaea and their potential impact on the saturation of membrane polyterpenes.

## Contribution

The study investigates the diversity and potential functions of geranylgeranyl reductase paralogs in Archaea.

## Key findings

- Geranylgeranyl reductases are linked to the saturation of polyterpenes in Archaea.
- The genomic loci and structure of geranylgeranyl reductase paralogs correlate with membrane polyterpene diversity.

## Abstract

The enzymology of the key steps in the archaeal phospholipid biosynthetic pathway has been elucidated in recent years. In contrast, the complete biosynthetic pathways for proposed membrane regulators consisting of polyterpenes, such as carotenoids, respiratory quinones, and polyprenols remain unknown. Notably, the multiplicity of geranylgeranyl reductases (GGRs) in archaeal genomes has been correlated with the saturation of polyterpenes. Although GGRs, which are responsible for saturation of the isoprene chains of phospholipids, have been identified and studied in detail, there is little information regarding the structure and function of the paralogs. Here, we discuss the diversity of archaeal membrane-associated polyterpenes which is correlated with the genomic loci, structural and sequence-based analyses of GGR paralogs.