Page 1 \ ?^p 6r.1 CELL CYCLE CONTROL OF HUMAN H4 ...

A2i2F: Cettcdt cotubtot e@IrNiotid
accessory lacrors. In eukaryotes it may be th6 accessory faclors rather uian
lhs polym6rase enzymes themsolves that are princlpaly reqlired for
fecognlzing th€ oNA sequenc€ component of rh6 promoter iniiialon site. The
common iearirre is that transcription tacrors bind ro the sequence elemenls
concenlrated upslream ot rhe ransciprion start poinr. Facrors binding ro DNA
Iom a complex in which protsin-prot€in interactions aro imponad RNA
polymeras€ binds as a part oi rhis cohplex and ihen inilialLon can slad at
p.omor€r sgquencss which are fequ r€d for initiation. anorhor rype of site is
.eqlired which enhances th€ inleraclion of such sequence caled
enhancer.The c€mponent ol enhancer resemble those of lhe promoler which
@nsist ol a variery ot orher elements. FNA Pol ll r .tlires some other
aclessory iactors lo nitiale lranscrlpiion. The TATA box re atsd iactor which
bi.ds to TATA bo( s r€qunsd to bind poym€.ase, TFllo, TFIIA TF lB and
TFllE. Since TFIIO binds dnectly to rhe TATA box and other lactors blndtolhe
Gsemblies complex and rhese laclors may be pan ol rhe rranscrip[on
apparatus which is imporlant lor assembling a complex ln which RNA
polym€raso is able ro i.itiare lhe lranscription,
The pfincipl€s operal ng rranscriptional regulallon ol prokaryolc (Jacob
and Monod, 1961; Glben and tMulter-Hill, 1966: Emm€r er a/., 1970) and
eukaryoric viral gsnes oooz€, 1981) hav€ bsen frmly esrablished. The inst
promoler ONA elements ol eukaryotic g€nes were idenlified by sequence-
alignmenG (Brealhnach and Chambon, 1981) and mulallonal analyses
(Grossch€dlsnd Sinstiel, 1980; McKnighl6nd Kingsbury, 19S2) oilhB regon