Science - USA (2022-01-21)

coronavirus 2 (SARS-CoV-2)

strains highlights the importance

of identifying antigen-binding

monoclonal antibodies rapidly

and accurately. Existing meth-

odologies are time-consuming

and laborious. Antanasijevic et

al. used detailed cryo–electron

microscopy structural analysis

of serum containing polyclonal

antibodies binding to an HIV

antigen in combination with next-

generation sequencing of B cell

receptors to identify HIV-specific

monoclonal antibodies. The novel

sequences identified from the

polyclonal serum were vali-

dated using antigen binding and

structural assays. This approach

requires that B cell receptor

sequences are available at the

same time that serum is collected

MOLECULAR MOTORS

Biphasic regulation of

kinesin-1 by MAP7

Motor proteins are differentially
regulated by microtubule-
associated proteins (MAPs)
to deliver intracellular cargos
to their destinations. MAP7
recruits the molecular motor
kinesin-1 to microtubules and
activates subsequent motility,
but the underlying mechanism
is unclear. Using cryo–electron
microscopy, Ferro et al. deter-
mined a near-atomic structure of
MAP7 on the microtubule. They
found that the microtubule-
binding site of MAP7 overlaps
with kinesin. However, by tether-
ing kinesin-1 to the microtubule,
the MAP7 projection domain

enabled the motor to diffuse to

available sites on microtubules

partially decorated by MAP7.

These results reveal the mecha-

nistic basis of MAP7-mediated

activation of kinesin motility

despite their competing binding

to tubulin. —SMH

Science, abf6154, this issue p. 326

SOLAR CELLS

Tailoring tin oxide layers

Mesoporous titanium dioxide is

commonly used as the electron

transport layer in perovskite solar

cells, but electron transport layers

based on tin(IV) oxide quantum

dots could be more efficient, with

a better-aligned conduction band

and a higher carrier mobility. Kim

et al. show that such quantum

dots could conformally coat a

textured fluorine-doped tin oxide

electrode when stabilized with

polyacrylic acid. Improved light

trapping and reduced nonradiative

recombination resulted in a certi-

fied power-conversion efficiency

of 25.4% and high operational sta-

bility. In larger-area minimodules,

active areas as high as 64 square

centimeters maintained certified

power conversion efficiencies of

more than 20%. —PDS

Science, abh1885, this issue p. 302

STRUCTURAL BIOLOGY

Identifying ideal

monoclonal antibodies

The emergence of new severe

acute respiratory syndrome PHOTO: REINHARD DIRSCHERL/ALAMY STOCK PHOTO

278 21 JANUARY 2022 • VOL 375 ISSUE 6578 science.org SCIENCE

Edited by Michael Funk

IN SCIENCE JOURNALS

Protecting connectivity

between regions is important

for maintaining biodiversity and

ecosystem services in coral reefs,

such as this one in Indonesia.

CORAL REEFS

Protecting connectivity

C

oral reefs are highly threatened by climate change and human pressure. Recent research has

focused extensively on how to protect reefs from these impacts, but a fact that is often missed is

that reefs are not isolated systems. Fish and coral larvae are actively exchanged across regions,

and some reefs supply more whereas others receive more. Fontoura et al. looked at the source/sink

dynamics of reefs globally and found that maintaining these networks, including dispersal corridors,

is essential for biodiversity conservation and sustainable fisheries. Furthermore, they found that the

majority of key source reefs and corridors remain unprotected. —SNV Science, abj8432, this issue p. 336

RESEARCH