ABSTRACT & LINKS
Marian CO, Bordoli SJ, Goltz M, Santarella RA, Jackson LP, Danilevskaya O,
Beckstette M, Meeley R, and Bass HW (2003)
The maize Single myb histone 1 gene, Smh1, belongs to a novel
gene family and encodes a protein that binds telomere DNA repeats in vitro.
Plant Physiology 133:1336-1350.
[
Plant Phys-online
|
PubMed ID
14576282
|
PDF+ (+ supplement)
|
At SMH gene family at TAIR
]
GenBank Accessions for full-length cDNAs:
Smh1 AY271659 |
Smh3 AY280629 |
Smh4 AY280631 |
Smh5 AY280630 |
Smh6 AY280632
ABSTRACT:
We screened maize (Zea mays L.) cDNAs for sequences similar to the single
myb-like DNA-binding domain of known telomeric-complex proteins. We identified,
cloned, and sequenced five full-length cDNAs representing a novel gene family and
describe the analysis of one of them encoded by the gene Single myb histone 1 (Smh1).
The Smh1 gene encodes a small, basic protein with a unique triple motif structure
of (1) an N-terminal SANT/myb-like domain of the homeodomain-like superfamily of
3-helical-bundle-fold proteins, (2) a central region with homology to the conserved
H1 globular domain found in the linker histones H1/H5, and (3) a coiled-coil domain
near the C terminus. The Smh-type genes are plant specific and include a gene family
in Arabidopsis and the PcMYB1 gene of parsley but are distinct from those (AtTRP1,
AtTBP1, and OsRTBP1) recently shown to encode in vitro telomere-repeat DNA-binding activity.
The Smh1 gene is expressed in leaf tissue and maps to chromosome 8 (bin 8.05), with a
duplicate locus on chromosome 3 (bin 3.09). A recombinant full-length SMH1, rSMH1,
was found by band-shift assays to bind double-stranded oligonucleotide probes with
at least two internal tandem copies of the maize telomere repeat, TTTAGGG. Point
mutations in the telomere repeat residues reduced or abolished the binding, whereas
rSMH1 bound nonspecifically to single-stranded DNA probes. The two DNA-binding motifs
in SMH proteins may provide a link between sequence recognition and chromatin dynamics
and may function at telomeres or other sites in the nucleus.
back to pubs page
HOME