G-quadruplexes are four-stranded DNA structures formed from G-rich sequences that are
built around tetrads of hydrogen-bonded guanine bases. Accumulating studies have revealed that Gquadruplex
structures are formed in vivo and play important roles in biological processes such as DNA
replication, transcription, recombination, epigenetic regulation, meiosis, antigenic variation, and maintenance
of telomeres stability. Mounting evidence indicates that a variety of proteins are capable of
binding selectively and tightly to G-quadruplex and play essential roles in G-quadruplex-mediated
regulation processes. Some of these proteins promote the formation or/and stabilization of Gquadruplex,
while some other proteins act to unwind G-quadruplex preferentially. From a drug discovery perspective,
many of these G-quadruplex binding proteins and/or their complexes with G-quadruplexes are potential drug targets.
Here, we present a general summary of reported G-quadruplex binding proteins and their biological functions, with focus
on those of medicinal research significance. We elaborated the possibility for some of these G-quadruplex binding proteins
and their complexes with G-quadruplexes as potential drug targets.