The second Lim domain of pollen specific protein SF3
The second Lim domain of pollen specific protein SF3: SF3 is a Lim protein that is found exclusively in mature plant pollen grains. It contains two LIM domains. The exact function of SF3 is unknown. It may be a transcription factor required for the expression of late pollen genes. It is possible that SF3 protein is involved in controlling pollen-specific processes such as male gamete maturation, pollen tube formation, or even fertilization. As in other LIM domains, this domain family is 50-60 amino acids in size and shares two characteristic zinc finger motifs. The two zinc fingers contain eight conserved residues, mostly cysteines and histidines, which coordinately bond to two zinc atoms. LIM domains function as adaptors or scaffolds to support the assembly of multimeric protein.
Comment:The two zinc fingers contain eight conserved residues, mostly cysteines and histidines, which coordinately bond to two zinc atoms. The Zn binding residues of LIM domain are highly conserved.
Jiyao W et al.(2023). "The conserved domain database in 2023.",