SUF

Suf is a three-letter term that can refer to multiple concepts depending on context. Among technical uses, it most notably denotes the SUF pathway in cells, a system for assembling iron-sulfur clusters, and it can also be used informally as a label for a suffix in linguistic annotations.

In biology, the SUF (sulfur mobilization) pathway is one of the major systems for assembling iron-sulfur (Fe-S) clusters in bacteria and plant plastids. It operates alongside the ISC (iron-sulfur cluster) pathway and is particularly important under conditions of iron limitation or oxidative stress. The SUF machinery includes proteins such as SufS (a cysteine desulfurase) and SufE (a sulfur shuttle), as well as the SufA, SufB, SufC, and SufD subunits that form the assembly scaffolding and carrier network. Fe-S clusters produced by this pathway are essential cofactors for enzymes involved in metabolism, DNA repair, and photosynthesis. The SUF system is especially prominent in organisms living under stressful conditions or in plant chloroplasts.

In linguistics and language technology, suf is sometimes used as an abbreviation or label for a suffix, the affix attached to the end of a word to adjust meaning or grammatical function. Examples of suffixes in English include -ed, -ing, and -ness; suffixation is a widespread morphological process across languages, contributing to tense, aspect, number, case, and derivation.

Because suf is context-dependent, its meaning varies with field and usage. When encountered, it is best to rely on surrounding text to determine whether it refers to the biological SUF system or to a linguistic suffix label.