Biology Reference
In-Depth Information
Table 8.2
Consecutive promoters in some
Anabaena
sp. strain PCC 7120 genes involved in heterocyst differentiation and function
Gene(s)
Comments
Reference(s)
cphB1A1
Operon expressed from three consecutive promoters. The one generating TSP -357 is a vege-
tative-type promoter, and those generating TSPs -339 (Class I NtcA-dependent, being the
main promoter used in heterocysts) and -499 are inducible and directly regulated by NtcA. In
addition,
cphA1
is expressed monocistronically from two vegetative-type promoters (TSP -89,
preceded by a −10 box and a UP element, and TSP -141 preceded by −10 and −35 determi-
nants) and a Class II NtcA-activated promoter (TSP -116), which is active in heterocysts.
Picossi et al., 2004
devBCA
Operon expressed from a proximal promoter (TSP -454) with a recognizable −10 box, depen-
dent on NtcA and HetR, directly activated by NtcA and induced in proheterocysts, and a
distal, Class II NtcA-activated promoter (TSP -704) induced in vegetative cells and, at higher
levels, in proheterocysts.
Fiedler, Muro-
Pastor, Flores, &
Maldener, 2001
;
Camargo et al.,
2012
glnA
Gene expressed from a vegetative-type promoter (TSP -155 or -157) preceded by consensus
−10 and −35 sequences, and at least two inducible promoters, of which that producing
TSP -93 represents a Class II NtcA-activated promoter and is the main promoter used in
mature heterocysts, and that producing TSP -267 (or −275) depends on NtcA and is pre-
ceded by a putative −10 box.
Frías et al., 1994
;
Tumer et al.,
1983
;
Valladares
et al., 2004
hetC
Gene expressed from a proximal promoter (TSP -293) directing NtcA- and HetR-dependent
increased expression localized to proheterocysts, which includes a putative −10 determinant,
and a distal inducible promoter (TSP -571) representing a Class II NtcA-activated promoter.
Muro-Pastor,
Valladares,
Flores, & Her-
rero, 1999
,
2009
hetR
Gene expressed from four consecutive promoters, a proximal one (TSP -184) active in the pres-
ence and absence of combined nitrogen and three inducible one producing TSP -
271 that depends on NtcA and HetR and shows increased activity mainly in the differentiat-
ing cells; one producing TSP -696 that requires neither NtcA nor HetR; and one producing
TSP -728 that shows a strong requirement for NtcA. The latter two show considerable induc-
tion both in vegetative cells and heterocysts. Putative −10 and −35 determinants can be
recognized upstream from the −184, −696 and −728 positions, and a putative −10 box
upstream of −271. NrrA has been described to bind at a sequence between −844 and −818.
Buikema &
Haselkorn,
2001
;
Ehira &
Ohmori, 2006b
;
Muro-Pastor
et al., 2002
;
Rajagopalan &
Callahan, 2010
