STPR, a 23-amino acid tandem repeat domain, found in the human function-unknown protein ZNF821.
The STPR motif is composed of 23-amino acid repeats aligned contiguously. STPR was originally reported as the DNA-binding domain of the silkworm protein FMBP-1. ZNF821, the human protein that contains the STPR domain, is a zinc finger protein of unknown function. In this study, we prepared peptides of silkworm FMBP-1 STPR (sSTPR) and human ZNF821 STPR (hSTPR) and compared their DNA binding behaviors. This revealed that hSTPR, like sSTPR, is a double-stranded DNA-binding domain. Sequence-independent DNA binding affinities and α-helix-rich DNA-bound structures were comparable between the two STPRs, although the specific DNA sequence of hSTPR is still unclear. In addition, a subcellular expression experiment showed that the hSTPR domain is responsible for the nuclear localization of ZNF821. ZNF821 showed a much slower diffusion rate in the nucleus, suggesting the possibility of interaction with chromosomal DNA. STPR sequences are found in many proteins from vertebrates, insects, and nematodes. Some of the consensus amino acid residues would be responsible for DNA binding and concomitant increases in α-helix structure content.
Nonaka
Yasuhiro
Y
Division of Biological Sciences, Graduate School of Science, Hokkaido University, Sapporo 060-0810, Japan.
Muto
Hideki
H
Aizawa
Tomoyasu
T
Okabe
Etsuro
E
Myoba
Shohei
S
Yokoyama
Takuya
T
Saito
Shin
S
Tatami
Fumie
F
Kumaki
Yasuhiro
Y
Kamiya
Masakatsu
M
Kikukawa
Takashi
T
Mizuguchi
Mineyuki
M
Takiya
Shigeharu
S
Kinjo
Masataka
M
Demura
Makoto
M
Kawano
Keiichi
K
D000596:Amino Acids / Q000235:genetics / Q000378:metabolism; D000818:Animals; D012831:Bombyx / Q000235:genetics / Q000378:metabolism; D004247:DNA / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics*; D006801:Humans; D017433:Protein Structure, Secondary / Q000235:genetics; D017434:Protein Structure, Tertiary / Q000235:genetics; D011506:Proteins / Q000235:genetics / Q000378:metabolism*; D020080:Tandem Repeat Sequences; D016335:Zinc Fingers / Q000235:genetics
D000596:Amino Acids; D004268:DNA-Binding Proteins; D011506:Proteins; C553000:ZNF821 protein, human; D004247:DNA