Structural domains comprising this superfamily share the structure of the nucleosome assembly proteins (NAPs), histone chaperones that are crucial for the shuttling and incorporation of histones into nucleosomes. NAPs participate in the assembly and disassembly of nucleosomes and therefore contribute to chromatin structure organization. Chromatin assembly and remodeling are vital cellular processes that are pivotal during replication, transcription, recombination, and repair in eukaryotic cells PMID:17360516.

Understanding NAPs mechanism of action is also key in the context of malaria as it is one of the most common infectious diseases and represents an enormous public health problem. Malaria is caused by protozoan parasites of the genus Plasmodium, and the most severe for of the disease is caused by Plasmodium falciparum. The plasmodium parasite genome encodes for two nucleosome assembly proteins, designated PfNapL and PfNapS, which are orthologs of eukaryotic NAPs and are present in all erythrocytic stages of the parasite. PfNapL forms complexes with both histone tetramer and octamer and is predominantly localized in the cytoplasm in the asexual and sexual stages of the parasite and, even though its itself is unable to deposit the histones onto DNA, it can interact with both core and linker histones and is involved in histone binding, shuttling, and transfer/release. PfNapL transfers cytoplasmic histones on to PfNapS. The key finding is that parasite NAPs are sufficiently different from their counterparts in other species and thus they constitute a unique opportunity for the exploration as anti-malarial targets PMID:19176479,PMID:20377878.